6 Best Electronic Water Descalers

Electronic water descaler is one of the newest salt-free water softener technologies that has become a very popular form of hard water treatment. It’s much more affordable than other water softeners like magnetic descalers and ion exchange water softeners.

The 6 Best Electronic Water Descalers

Water DescalerCapacity
Eddy ED6002P-USAny grain
SANIA YARNA Capacitive20 grains
HQUA 5000E20 grains
iSpring ED200019 grains
Scalewatcher Nano Original20 grains
HydroFLOW HS3870 grains

Eddy ED6002P-US

Eddy ED6002P-US

Eddy is one of the leading and most popular electronic descaling device manufacturers in the world. Their ED6002P-US which tops our list is amongst the best electronic water descaler you can find in the market.

The unit presents a simple yet effective solution for removing the adhesive properties of limescale and preventing scale buildup. Also, it’s capable of dissolving existing deposits and offers other amazing benefits as you are going to see below.

Softening Capability

The Eddy ED6002P-US is a simple electronic water descaler system that utilizes electromagnetic waves to prevent the formation of limescale.

The system features an electronic control box and two signal cables that are wrapped around the piping on your incoming water supply line. 

As the incoming water containing calcium carbonate and other minerals responsible for limescale deposits passes through the coils (signal cables), it’s subjected to a continually changing electromagnetic field that results from the two coils

This field effectively hits and agitates the molecules of the mineral thereby altering their adhesive properties and breaking the bonds between them and water.

The large mineral crystals likely to form scale are broken down into tiny mineral particles preventing them from interacting and reacting with other surrounding minerals.

In this way, they are unable to bond or adhere to any surface and they don’t precipitate out as hard scale hence preventing the formation of limescale inside pipe works and appliances.

The Eddy ED6002P-US is so effective that it will not only stop limescale formation by incoming water flowing through the pipes, but it will also help to progressively break down and flush away existing limescale in your pipes and water fittings in due course of time.

Another nice thing is that nothing is added or removed during the process hence the chemical composition of the water does not change.

It inhibits limescale formation without eliminating the hard water minerals which means you will still have healthy minerals like calcium and magnesium present in your water. No wastage or brine is discharged, so it’s equally environmentally friendly.

Moreover, this Eddy system is capable of delivering great results at water hardness levels of up to about 20 GPG which is the highest level on the water hardness scale. Therefore, it can effectively deal with average to high hard water levels.

Power Consumption

Being an electronic device, the Eddy ED6002P-US water softener system runs entirely on electricity and it will need a 110 volts power outlet to operate.

The good thing though is that it only consumes around 5 watts which is almost the same as a night light. In other words, it’s a low-power usage system and as such, you won’t have to worry much about power consumption because it will hardly cost anything to run it.

Installation and Maintenance

Anyone can literally hook this Eddy water descaler up within a few minutes. The installation is a very easy DIY process with no plumbing required.

It’s small and light hence doesn’t require a lot of space to install it and the cables are sufficient for winding around pipes with a diameter of up to 1.5 inches, which covers most domestic water feeds that measure either 1 inch (25mm) or 1.5 inches (38mm) in diameter.

Even much better, the unit is maintenance-free. It doesn’t need setting or monitoring like other systems plus since it’s entirely electric, there’s no hassle of having to regularly swap out batteries.

In terms of compatibility, the unit will work on both plastic and metal pipes, including copper and PVC. However, it’s not ideal for use on lead and iron piping because the removal of scale can cause the leaching of lead into your water, which can have serious health impacts.

Now the biggest advantage of this model is the highly favorable warranty terms it comes with. The company offers a lifetime warranty that covers repair and replacement. In addition to this, you also get a 1-year money-back guarantee which is a clear demonstration of the quality and durability of the unit.

One thing to note though is that you will not be able to use this system outside because it’s completely electric and not waterproof, so placing it outside means a severe fire risk.

All in all, this is an efficient and user-friendly salt-free water softener for descaling. If you experience average to fairly high levels of water hardness in your home, then the Eddy ED6002P-US model is certainly worth your consideration.


  • Effectively inhibits limescale build-up
  • Removes existing limescale from pipes and fittings
  • The healthy minerals are retained in your water
  • Low power usage system consuming only 5 watts
  • Great for average to high water hardness levels (up to 20GPG)
  • Environmentally friendly and no water wasted
  • Easy to install and completely maintenance-free
  • Works on almost all types of water pipes
  • Comes with a lifetime warranty along with a 1-year money-back guarantee


  • Not recommended for use on iron and lead pipes
  • Not waterproof hence cannot be mounted outdoors

SANIA YARNA Capacitive CWD24

SANIA YARNA Capacitive CWD24

The SANIA YARNA capacitive electronic water descaler is a feature-laden water softener system built to give exceptional effectiveness and work in compact spaces. It’s a unit that offers wonderful value for money.

Softening Capability

This YARNA capacitive electronic water descaler from SANIA is an innovative system that uses capacitive technology to effectively treat water hardness with electric impulses.

It’s made up of just two copper tapes and a tiny two-inch electronic unit. The copper tape cables are wrapped and secured around your main water supply pipe and connected to the electronic unit.

This electronic unit contains a computerized microchip that generates and controls electric impulses transmitted through the copper coils that wind around the water-supplying pipe. The bands interact and in the process, they form a frequency field.

Therefore, as the water flows beneath the two impulse coils, the powerful electric waves interfere with mineral molecules in the water causing them to lose their adhesive ability and break down large mineral crystals reducing them to minuscule sizes.

They transform calcium, magnesium, and other minerals that cause scale into ions. As a result, these minerals can’t adhere to anything as they can no longer bond to form scale, so there will be no limescale buildup in your pipework and appliances after you install this unit.

YARNA does not remove these healthy minerals while breaking them down into tiny particles to reduce their damage. They are necessary to ensure a healthy body and YARNA retains them in the water once the hardness problems are treated.

The major highlight of this unit, however, is that it uses a capacitive effect and a high-frequency range (3-32 kHz) which means it is effective at treating almost any grain or rather any water hardness level.

Highly Efficient System

Copper treatment bands are a very crucial factor as far as the performance of a capacitive electronic water descaler is concerned.

You need a unit that can generate a strong electric field along with a very efficient way to apply that to the water via the pipe. This YARNA system provides exactly that.

It uses special isolated copper impulse bands which are designed such that they firmly connect to the pipe. They are flat, wide with minimized isolation, and have very thin insulation. This way, they maximize the direct-contact ratio with the pipe to 97.5%.

This optimum contact area between the flat copper coils and the pipe facilitates a very efficient energy transfer which enables this YARNA water softener system to treat up to 3500 liters of water per hour or 15.4 gallons per minute to a 99% efficiency. It offers the best possible transfer output.

Power Consumption

The YARNA electronic water descaler requires a 120 volts power outlet to operate efficiently. The amazing thing is that it consumes just 4 watts of energy hence there will no large burden on your pocket when it comes to electricity bills.

Installation and Maintenance

You do not need technical skills or any tools to set up this YARNA unit. Like almost all electrical water descalers, the installation is a straightforward process that should take less than 10 minutes to complete.

The system is compatible with any pipe type including copper, stainless steel, iron, PVC, plastic, and compound pipes. It requires a minimum of 10 inches of free pipe space to wrap the coils and a maximum of 2 inches of pipe diameter which typically accommodates most households’ incoming water pipelines. 

In addition to that, the unit will not need any maintenance after installation and it’s made using high-grade CNC aluminum to ensure it lasts for years.

It can serve you for more than 10 years due to the quality of the materials used plus it’s backed by a 10-year warranty. If you are not satisfied with its performance, YARNA offers a whole year money-back guarantee where you can return it and get a full refund.

There are no serious setbacks we could point out as it’s really well made and does its work as expected. Perhaps the only is that you can’t install it outdoors. It’s IP44 rated meaning that it can take some moisture or water splashes but certainly not the rain.

In general, the YARNA capacitive electronic water descaler is a unit we would recommend to those who want something that can handle all kinds of water hardness because it doesn’t have any GPG limit. It’s a highly reliable salt-free water softener that will do its job efficiently.


  • Completely stops limescale buildup
  • Healthy minerals are not removed
  • Doesn’t have a particular GPG limit
  • Low power consumption at only 4 watts
  • Super-easy to install and needs no maintenance
  • Works best on any type of water pipes
  • Backed by a 10-year warranty with a 1-year money-back guarantee


  • Can’t be installed outdoors

HQUA 5000E Electronic Water Descaler

HQUA 5000E Electronic Water Descaler

Coming in third on our list is the HQUA 5000E electronic descaler which is carefully designed to provide great performance and efficiency in preventing and eliminating scale in piping works and appliances.


The HQUA-5000E unit presents a complex technology system that ensures frequency-regulated electromagnetic waves are generated to descale hard water.

This is accomplished through two cables that are wrapped around your main water pipeline. When powered, frequency-modulated electromagnetic fields are generated by the main unit and transmitted via the wrapped cables.

The waves effectively break down the structure of dissolved calcium carbonates and other minerals in the water through a process called resonance.

Through resonance, the broken calcium carbonate crystals lose their adhesive quality and stay freely in water as ions instead of sticking on the surface of the fixtures hence preventing the development of limescale in water pipes and enabling smooth water flow.

Simultaneously, the carbon dioxide released from water continuously dissolves existing scale buildup at the same time inhibits rust deposits in the water pipes and appliances. However, it might take a period of normally 1-3 months to get totally clean pipes and water fittings.

Comparatively, it is important to note that HQUA 5000E it’s a chemical-free system with no addition or removal of salt or other chemicals. For this reason, water composition is not deprived of essential minerals such as calcium and magnesium.

This electric descaler is capable of handling an entire water system with a maximum water hardness of 25 GPG. It’s best suited for the whole house consisting of up to 7 members.

Power Consumption

The HQUEA-5000E is an energy-saving system consuming only 4 watts of electricity which is considerably low compared to other electrical softeners. It will cost you around 5 to 7 dollars per year to operate it, so you get to save on electricity bills. The unit will work with a standard 110 volts power supply.

Installation and Maintenance

Requiring no skills at all, this HQUA model won’t pose any challenge as far as installation is concerned. You just need to mount the main unit near your power supply and wrap the two cables around the water supply pipe at the entry of your plumbing system and you are done.

The cables are long enough to wrap around the main water pipes not exceeding 1.5 inches in diameter. Furthermore, the unit can be used with all types of pipes from iron to copper, galvanized, plastic, and stainless steel.

In terms of maintenance, the unit is designed for zero maintenance, and a one-year limited warranty is offered from the day of purchase to cover any kind of defects in terms of repair or replacement.

However, like many other electronic descalers, this one is not waterproof, so you can only install it indoors and away from a water splash to be on the safer side.

All things considered, the HQUA 5000E electronic water descaler is an option we would recommend for anyone who wants a decent salt-free water softening system that can solve hard water problems.


  • Works effectively with hard water levels of up to 20 GPG
  • Prevents limescale and rust formation
  • Gradually removes existing limescale build-up
  • Retains healthy minerals
  • Energy-efficient consumes only 4 watts
  • Easy to install with zero maintenance
  • Compatible with various types of pipes
  • Comes with a 1-year limited warranty


  • Not waterproof

iSpring ED2000 Electronic Descaler

iSpring ED2000 Electronic Descaler

iSpring is a household name when it comes to producing top-tier water treatment products, and their ED2000 electronic descaler is no exception.

This is a smartly engineered electronic device that strikes a nice balance between efficiency and performance. For those on a budget and looking for the best electronic water descaler for their money, this is an option you may want to consider.

Softening Capability

The ED2000 utilizes an innovative hardness removal system that features two antenna cables wrapped around the main water pipe creating a coil and a computer chip that generates a complex, frequency-modulated electromagnetic waveform.

This waveform matches the resonant wave frequencies of the water molecule clusters, resulting in the breakdown of the clusters into active twin molecules that have a larger surface area and can bond much better with the hard mineral ions.

In this new state, the water molecules are able to pick up and carry hard mineral ions while preventing the likelihood of them adhering to pipe surfaces.

This process also naturally clears out the existing scale as the unsaturated water continually dissolves the scale deposits along the pipe causing them to begin breaking down and get removed completely from the water system.

Limescale deposits on your faucets, showerheads, and sinks will easily wipe off over time plus there will be no new scale deposits throughout your water supply lines and appliances. 

It will prevent the water molecules from binding together and re-forming larger clusters that create limescale deposits while still leaving the healthy minerals in the water.

The system can handle hard water levels of up to 19 GPG, so it’s built for very hard water areas and is capable of descaling an entire water system of a household.

However, for water traveling more than 50 ft., you may need a second ED2000 unit farther down the plumbing line to guarantee effectiveness.

Power Consumption

The ED2000 system is powered by a small transformer that is compatible with a 110-power supply outlet. The best part though about this iSpring electronic descaler is that it’s highly energy-efficient, it’s the second most efficient unit on this list.

It only consumes around 1.8 watts which significantly helps keep your total energy consumption down. It saves energy while still helping prolong the life of your water system and appliances.

Installation and Maintenance

This unit is very easy to install and use. No plumbing is required and it doesn’t need any maintenance. As for compatibility, it can work with almost any type of piping from copper to PVC, PEC, CPVC, and galvanized pipe. The cables require a maximum of 1-inch pipe diameter. If it’s between 1 to 1.5”, then you may have to use two ED200 units.

Aside from having no effect beyond 50 feet, the only other possible drawback about this iSpring system is that it may not perform effectively if your source water has high iron content. It can handle anything below 0.3 ppm but above that, it’s recommended you install an iron removal filter before the ED200.

Overall, for those on a budget and who want an efficient, and reliable salt-free water softener the iSpring ED200 electronic water descaler is a perfect choice. It’s solidly built and more than capable of descaling an entire water system and stopping further scale buildup.


  • Dependable descaling process
  • Eliminates existing limescale deposits
  • Retains the healthy minerals in the water
  • Very energy efficient using only 1.8 watts
  • The simple installation process with no maintenance is needed
  • Works with almost any type of water pipe
  • Comes with a 1-year money-back guarantee plus lifetime support


  • No effect beyond 50 feet
  • Not recommended for water with an iron content level above 0.3 ppm

Scalewatcher Nano Original Electronic Descaler

Scalewatcher Nano Original Electronic Descaler

The Scalewatcher Nano descaler’s first patent was granted in 1991 making it the first water descaler of its kind. Being the 12th version of its original design, this unit is now more effective than ever, and impressively long-lasting too.

Softening Capability

The Scalewatcher descaler is specifically designed to generate an electric field using its two cables wrapped together around the inlet of the main pipeline system. It descales water by inducing strong electric and magnetic fields with an endless changing frequency.

The system forces the naturally dissolved minerals in water such as magnesium and calcium ions to break down from large clusters (that form hard scales) to tiny crystals that cannot stick on the surface of piping, heating devices, and other fixtures.

The now unsaturated water causes the mineral ions to flow freely along with the water throughout the home plumbing system without any formation of limescale.

Additionally, the proficiency of the water to continually dissolve minerals is increased as a result of this process. Therefore, the existing hard scale is gradually dissolved and eliminated from the water system and other appliances like showerheads and faucets.

The system doesn’t compromise the mineral composition of water with harsh chemicals or salt. It leaves the treated water unchanged and retains the essential minerals inside it making it healthy to drink.

Scalewatcher works effectively with water hardness levels lower than 20 GPG. Usually, it performs best in municipal water supply since its water is always softened to an extent. However, if your water source is a private well, you may have to consider a stronger unit for the best results.

Power Consumption

This system includes an adapter that’s compatible with a 110v power supply outlet. However, it will consume up to 13 watts of power which means it will cost you less than $14 a year to operate.

When you put it side to side with the other models on this list, it’s certainly not the most energy-efficient system. Nonetheless, at $14 a year, it’s safe to say that you will not have to dig deep into your pocket to run it. 

Installation and Maintenance.

This compact system offers hassle-free installation with no plumbing or electrician required and takes up very little space. You can use it with various types of piping including copper, steel, and PEX or PVC pipes.

It requires a maximum of 1.5 inches of pipe diameter and you need 6 to 7 inches of pipe space to wrap the coils. It works smoothly on a 16 to 22-meter-long water pipeline system.

The entire system descales your water and improves the efficiency of your heating appliances with no maintenance required. It includes two red and green LED indicator lights that notify you if the system works fine.

On the negative side, it is notably designed for indoor use only and it may not work effectively if your source of water has a high level of hardness beyond 20 GPG. Other than that, the Scalewatcher Nano descaler is a functional and durable unit that can efficiently help keep your water, plumbing system, and appliances free from limescale.


  • Prevents scale build-up and eliminates existing deposits
  • Can handle water hardness levels of up to 20 GPG
  • Retains healthy minerals deposited in the water
  • Compatible with various types of pipe
  • Quick installation and no maintenance required
  • Comes with a 2-year warranty for repair and replacement


  • It’s not waterproof
  • Not suitable for well water
  • Not the most energy-efficient system

HydroFLOW HS38 Descaler

HydroFLOW HS38 Descaler

If you have a small apartment, home, or RV, the HydroFLOW HS38 might just be the right unit for you. It’s the most compact and convenient electric descaler on our list with a unique design and softening technology that not only makes it stand out but is also very effective.

Softening Capability

The HS38 features a rather different technology and design from that of other electronic water descalers on the market. It has no copper bands or signal cables that require wrapping around the main water supply pipe.

It’s a single compact unit with two sections that are secured to the pipe using a clip. The system works by inducing robust but harmless signals of around 150 kHz into the water as it flows through the pipes.

Due to the conductivity of water, the electric field is transmitted throughout the plumbing system. These electric waves work within the water to agitate the scale-forming mineral ions causing them to break down into fine, stable crystals in suspension rather than turning into the problematic scale.

The induction of the signals totally stops scale from accumulating inside the plumbing system and as well gradually removes the existing deposits already in the system.

It’s an innovative and super-effective technology, and the main secret behind this is the fact that it uses water as a conduit which enables the signal to propagate throughout the whole system.

Therefore, all the places that the water passes through get to be effectively protected and treated which is a big plus considering that other models that rely on the pipe or wire wrap to transmit the signal only treat the water passing under the wrapped area. 

Another amazing thing about this unit is that the signals induced into the water are capable of agitating and removing biofilm layers formed as a result of bacteria and algae attaching to the piping. Over time, the signals will release any traces of biofilm in your pipes which will then be flushed out of the system alongside any existing scale.

Moreover, this HS38 descaling process is capable of inhibiting up to 65% of internal pipe corrosion. When installed on metal pipework, the current passing along it will create a coaxial magnetic field which interferes with the electrochemical reaction required for corrosion to take place.

The unit can remove hardness levels of up to 70 GPG which is pretty high since anything over 20 GPG is considered extremely hard. It does soften the water without changing its physical makeup, thereby you will also have the healthy minerals present in your water.

Power Consumption

With regards to power consumption, the HydroFLOW HS38 takes the upper hand compared to the other models herein. It uses not more than 1.2 watts which is the lowest power consumption.

This means you will get to save a lot of money because it will cost you approximately $3 to run it for a whole year and it connects to a standard 110 volts power supply.

Installation and Maintenance

With only a single unit with no cables to wrap around pipes, the HS38 is designed for nothing but convenience and ease of installation. It simply clips around your existing pipe, and you just need a screwdriver and outlet to install it within a few minutes.

It fits up to 1-inch pipe diameter and requires around 2 to 3 inches of clearance. You can also connect it to different types of pipes including copper, PVC, PEX, and galvanized pipes.

According to HydroFLOW, it’s recommended to install this unit indoors, but it can also be installed outdoors provided it’s properly protected from the elements. You will have to ensure the entire unit plus the power supply, is well covered.

The system doesn’t require maintenance at all and it comes with a red LED light indicator that glows brightly to let you know the signal is propagating through the plumbing system. Therefore, you can easily tell when it’s working or not working.

Generally, the HydroFLOW HS38 is an electrical water descaler built to suit those looking for a tiny system that’s more than capable of dealing with extreme water hardness. It’s a convenient option, especially for RVs, small homes, and apartments measuring up to 1200 sq ft.


  • A very effective descaling process removes hardness of up to 70 GPG
  • Eliminates existing scale and biofilm throughout the water supply system
  • Keeps the healthy minerals in the water
  • Highly energy-efficient consuming only a maximum of 1.2 watts
  • Installation is straightforward and requires zero maintenance
  • Comes with a 3-year warranty against defects or failure


  • Not suitable for larger homes

Electronic Water Descaler

Best electronic water descaler

An electronic water descaler is a salt-free electronic device consisting of coils of insulated electrical cables wrapped around the pipes at your main water inlet. They produce electromagnetic waves that alter the chemical structure of the water minerals thereby preventing limescale from attaching and building up in the pipes.  

The electronic water descaler is made up of an electronic box that is connected to two electrical cables, also known as antennas which are coiled around the pipes at your main water inlet.

The electronic box passes an alternating current (once positive, once negative) through the cables wound around the pipes. In turn, the alternating current generates electromagnetic waves that interact with the incoming water molecules passing through the pipes.

A common electrical cable has two parts, the outer insulating part (polymer) and the inner conduction part which is the copper wire. When the positive current goes through the copper wire (inner conduction part), the outer insulating part becomes negatively polarized.

Therefore, the water molecules which pass through the pipes are attracted and repelled successively, and as such, the cations and anions present lose their affinity for water. They break away from their existing association and disperse.

This way, the electromagnetic waves prevent the calcium and magnesium ions in the water from forming calcium and magnesium carbonate which are the main cause of limescale deposits in plumbing systems and appliances.

Instead, the dissolved bicarbonates and dissolved solids like calcium crystallize to form non-scaling microcrystals which do not adhere to the pipes, taps, and kettles, thereby effectively preventing scaling.

Benefits Of An Electronic Water Descaler

Installing and using an electronic water descaler at your home offers several benefits which include:

Helps Extend the Life of Appliances and Pipe Work at Home

Hard water causes the buildup of limescale on the pipework at home which includes the water-using fixture, sinks storage tanks, water heaters, radiators, tubs, shower pipes, washing machines, and dishwashers.

This accumulation of hard water scale can significantly shorten the life of these appliances leading to more frequent replacements which can prove costly over time.

Salt-free water softeners can effectively reduce and prevent the buildup of limescale on your home’s pipes and appliances which not only helps extend their life but also means less costly repairs which can save you plenty of money and headaches over the long term.

Does not Influence Water Quality

Electronic water descalers add no chemicals or salt into the water. Aside from the electromagnetic waves, it doesn’t interact with the water in any way and as such, they don’t affect the quality of the water as it passes through the pipes.

For those who have cardiovascular issues or need to monitor their sodium intake, using an electronic water descaler can also be beneficial since they don’t add or produce sodium during the descaling process.

Salt-based softeners, on the other hand, leave some sodium in your water after treatment while with an electronic water descaler, you are only left with the natural sodium present in the water.

Leaves Essential Minerals

Electronic water descalers don’t remove the important minerals which are beneficial to your health. All the essential minerals like calcium, potassium, and magnesium simply crystalize to eliminate the problems of water hardness, so they remain intact in your water.

Therefore, if you need to prevent limescale buildup and still leave the healthy minerals in your water for consumption, then you can rely on an electronic water descaler.

Affordable Pricing and Low Operating Costs

Compared to other water softeners, particularly salt-based systems, electric water descalers are low-investment devices. They are very much more affordable than ion-exchange water softeners with some models even costing almost half the price of standard salt-based systems.

Another bonus is that they only require limited electricity to run and use much less water without producing any discharge.

Thereby, they are less costly to operate and can save you money. Salt-based systems use much more water and require frequent replacement of salt and other chemicals, all of which will cost you money.

The replacement salt bags are also not that cheap which makes them relatively more expensive to operate than electric water descalers.

Easy to Install and Very Low Maintenance

Salt-based systems are large bulky units that require drainage and a lot of space to install and operate. However, salt-free systems like electric water descalers are much more compact and easy to install.

They don’t need remodeling your plumbing to accommodate them as they can fit almost anywhere and have fewer moving parts.

The best part is that they require very low maintenance than salt-based systems. They can run unsupervised for long periods and there are no salts or other chemicals that need regular replacements.

Salt-based systems require in-depth maintenance and constant monitoring since you will have to attend to the unit at least once every week to replace the salt which is quite a hassle.


One of the major impacts of limescale build-up is the reduction of the efficiency of your plumbing system and water heating appliances. By installing a quality and reliable water softening system, you can eliminate and help prevent these problems.

Salt-free water softeners, both water descalers, and water conditioners provide a great alternative option to traditional salt-based systems. They are effective, relatively affordable, and reduce the need for expensive salts as well as frequent monitoring and brine washing.

If you have read our reviews above and compared the different options we’ve listed, then we believe you will have little difficulty evaluating and choosing the best electronic water descaler that will meet your needs.

One thing you want to make sure though is that you take into consideration the water condition in your home before settling on a particular model.