12 Best Pool Heaters Consumer Reports of 2021: Review and Buying Guide

Most American homes have either a pool, a spa, a bathtub, or any combination of these. However, no one wants to step in cold water, especially during the chilly months or cold nights.

Even during a sunny day, the pool’s temperature can fall below the comfortable high 70s. It’s why water heaters are a must-have possession for many households.

Nevertheless, gas-fired pool heaters are an oddity because they heat pools fast, but leave high bills. The best pool heater is one that produces heat that equals or exceeds the power input.

Top 5 Best Pool Heater: Editor Pick’s

Fortunately, newer, more efficient models enter the market every day, and making the right choice is tough.

Worry not.

Our pool heater review is a product of long hours of research, analysis, and tests to recommend the best pick that fits not just your purpose but budget.

The Best Pool Heater Guide

Swimming pool heaters come in different shapes and sizes. The market is rich in models, but the most popular are gas and electric models, although the popularity of solar has been steadily rising in the wake of skyrocketing fuel costs.

Best Pool Heaters Consumer Reports Reviews:

1. Hayward H400FDN Universal H-Series

Hayward H400FDN Universal H-Series
718 Reviews
Hayward H400FDN Universal H-Series
  • Standard Cupro nickel heat exchanger for superior value and reliability
  • Patented polymer header and bypass valve design for the ultimate in hydraulic efficiency and reliability
  • Hayward Universal design for easy and versatile professional installation
  • Environmentally responsible low NOx emissions to meet or exceed air quality emission standards in all Low NOx regions

The H400FDN is today’s gas-fired heater with higher efficiency than older models. Yet, even the most efficient pool heaters don’t come close to solar and heat pump pool heaters in utilizing the energy input.

However, don’t be quick to write off the 197-pound beast of a machine. For sure, Hayward will entice you when you intend to heat your pool quickly – not when you want to heat regularly, as costs can spiral out of control.

Hayward’s usable output of the British thermal unit (Btu) is high, at 400,000 Btus. Therefore, when you own a pool in places, which experience cold nights, high average wind speeds, and low humidity, with such a high Btu rating on your side, you don’t have to worry.

When wind speeds clock 3-1/2-mile per hour, you can expect the best pool warmer for quick heating to raise pool water temperatures by a cool 1-1/4 degrees Fahrenheit per hour when you use a 75,000-Btu-rated gas pool heater!

Think about how much temperature rise you would achieve when you use a 400,000-Btu-rated pool heater. However, if you own a small tank, you may need to purchase and replace it with a new one regularly, which drives up costs.

While cost-competitive with electric swimming pool heaters, the Universal H-Series is a practical option if natural gas or propane is available in your area. It’s also the costliest alternative in the same product line, at slightly over $4000.

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2. GAME 4721-BB Solar PRO Curve Solar Pool Heater

GAME 4721-BB Solar PRO Curve Solar Pool Heater
899 Reviews
GAME 4721-BB Solar PRO Curve Solar Pool Heater
  • SOLAR POOL HEATER: The GAME SolarPRO Curve Solar Pool Heater has been designed for above-ground and most inground pools. It increases the pool temperature by 5 degrees in 4 days (for an 8,000-gallon pool).
  • DURABLE CONSTRUCTION: We’ve designed this above-ground solar pool heater with high-quality materials that will hold up against frequent exposure to the sun and outdoor elements.
  • UNIQUE CURVED SHAPE: The GAME solar pool heater has been engineered with a unique curved shape that maximizes heat collection. The treaded ports have been added for versatile plumbing options.
  • ADJUSTABLE LEGS: This solar heater is compatible with Intex, Bestways, and most above and inground pools. The adjustable and foldable legs allow the heater to be set for maximum exposure to the sun, along with a clear cover that locks in heat.
  • THE PERFECT GRADUAL HEATER: This solar pool heater is not intended to be a miracle-cure heater. It’s designed to extend your pool season by gradually increasing the water temperature by a few degrees. Maximum heat output with space saving footprint

When skyrocketing fuel costs tire you, and you want to prolong the swimming season, which usually occurs between mid-June and July, you need the most economical alternative available.

The cost-competitive option to heat pump and gas pool heaters is a real deal if you no longer intend to leave your outdoor pool to the whims of the weather.

Game 4721-BB is a solar pool heater that ticks off all the checkboxes. Sun energy is free of charge! You don’t need to meet the monthly utility bills.

The 12.45-pound collector is hands down the absolute best pool heater if you are looking for a simple design and parts. You can expect the sun’s rays collector to raise the temperature of an 8000-gallon-capacity pool by 1-1/4 degrees Fahrenheit every 24 hours.

You don’t have to face the pain of swimming in a chilly pool and meeting high energy costs. While the 4721-BB doesn’t have all the bells and whistles, its simplicity is also the greatest undoing.

You will need more than one collector if you want to raise the temperature quickly, which accounts for additional costs. Once you size your pool, while the upfront costs are massive, they are one-time.

The solar pool heater also attracts an incentive rebate, which cuts down on installation costs. You will also need to sacrifice shade for sunlight, which isn’t always a viable option.

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3. Hayward FDXLBKP1930 Universal H-Series

Hayward FDXLBKP1930 Universal H-Series
640 Reviews
Hayward FDXLBKP1930 Universal H-Series
  • Excellent salt water and chemical corrosion resistance
  • Same water velocity through all tubes for faster heating
  • Up to 18% savings by reducing pump run-time. Low NOx emissions meets clean air quality standards
  • Common union for installation or service, adapts to larger plumbing recommended for greater efficiencies
  • Recommend that the repair or replacement of components in gas fired, electrically powered devices be performed by a qualified technician for the safety purpose

When you notice a sharp spike in energy bills, then your swimming pool heater’s efficiency has decreased, or something may have broken the system.

Several factors cause your swimming pool heater to malfunction. Inadequate maintenance, salty (corrosive) water, electrical bugs, pests, rust, leaks, and control failures make your pool heater to misbehave. Replacing a buggy pool heater doesn’t come cheap.

That’s why the pool heater replacement part for Hayward is a lifesaver. The FDXLBKP1930 is what you need to ensure the durability and efficiency of your pool heater and to reduce the likelihood of a faulty system.

It’s a spare part that fixes not just the leaking and heating, but other problems as well. However, replacing the flaws requires a pro because it’s a risky job.

Even the best pool heater emits a gas, which can ignite and cause injuries. Carbon monoxide and nitrogen oxides are examples of poisonous emissions.

Therefore, ensure replacement takes place in a space with proper ventilation or in an open space. And the replacement kit isn’t costly, yet it can save you from incurring huge costs of repairing a pool heater with lots of flaws.

In short, the Hayward FDXLBKP1930 prevents errors from building up. In under 3.84-pounds, Hayward is a small and lightweight device that can do big things. Hence, it’s a must-have for anyone who owns a swimming pool heater and wants to enjoy a consistent experience.

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4. Sun Heater Pool Heating System S240U

Sun Heater Pool Heating System S240U
  • SOLAR POOL HEATER – The SunHeater Solar Pool Heating System allows you to capture free heat from the sun’s rays to effectively raise your pool water temperature. It’s an efficient and cost-effective method to heat your pool.
  • EXTENDS POOL SEASON – Your pool’s pump pushes the water through the panel’s many tubes where it’s warmed by the sun and then returned into the pool. This system can raise the water temperature 6-10 degrees F and extend your pool season by weeks!
  • EASY TO INSTALL – This pool solar heater uses your existing filtration system and has 4 end caps, 2 elbows for flex hose connection, 6 stainless steel hose clamps, 1 roll of Teflon tape, and rubber connector hoses.
  • TUBE ON WEB DESIGN – The tube-web-tube design allows the SunHeater to capture the most sun possible, maximizing square footage. It offers rigid flexibility, allowing panels to expand and contract with changing temps, giving it the strength needed to last.
  • DIMENSIONS – The SunHeater Solar Pool Heater includes two 2’ x 20’ panels, made of durable polypropylene. It’s a universal system that works for pools up to 31’ round or 18’ x 36’.

The S240U features two 2″ by 20″ collectors, which don’t come with a glass covering. Sun Heater treated the heavy-duty polypropylene with an ultraviolet light inhibitor to elongate its lifespan.

The best swimming pool heaters of its ilk are often longer-lasting than the heat pump and gas models. Also, if simplicity and spending are your main concerns, then the Sun Heater S240U is a viable option because its components are inexpensive, and its design is simple.

You will delight in the best pool heater for swimming in temperatures that exceed 32 degrees Fahrenheit. Cold weather shouldn’t dissuade you from using the model because it works in indoor pools with a design that allows the system to drain back to the water when idle.

Shutting down the pool heater in chilly weather doesn’t make collectors less cost-effective. However, without the glazing, sunray collection during the cold weather is inefficient.

Thus, you can’t use the model year-round. While initial installation costs can be somewhat budget-unfriendly, monthly utility bills are zero afterward. The only expenses you will incur are operational, and they are minimal.

Even if your pool’s location isn’t a sunny and warm place, you may be able to trap the sun’s rays. However, if your building site faces north, or has a shady surrounding, or both, then solar pool heaters aren’t amenable.

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5. Pentair 42001-0053S Electrical Systems

Pentair 42001-0053S Electrical Systems
577 Reviews
Pentair 42001-0053S Electrical Systems
  • Genuine Pentair replacement part
  • Fits Pentair Sta-Rite Max-E-Therm pool and spa heaters electrical systems
  • Also fits Pentair MasterTemp pool and spa heaters electrical systems

If your swimming pool’s electrical system is faulty, then you need a quick fix. Pentair model 42001-0053S hits all the marks. It just weighs 1.41-ounces, so it’s very light.

Even if your pool heater fires off consistently, it doesn’t mean it’s faultless. If your pool heater runs for short periods or switches itself off, then its electrical system has flaws.

And the thermostat is the usual culprit, although the problem could also lie with the temperature sensor. The thermostat maintains the pool temperature.

Pool heater components such as the heat sensor or thermostat are not simple because they handle large volumes of water in contrast to smaller quantities in bathtubs, spas, and Jacuzzis.

And so, it’s a big deal when they break. It’s a costly affair to replace a pool heater, although you can troubleshoot the problem when you notice the tell-tale signs.

Pool heaters often come with manuals that guide troubleshooting. Alternatively, you can conduct tests. The good news is, in-depth information to calibrate or replace the faulty thermostat is available online.

Check the thermal regulator for scaling, faulty electrolysis, and corrosion. They are problems inherent in water chemistry, and they usually cause thermostat problems.

The thermistor comes in handy in minimizing risks. The Pentair is compatible with electrical systems of spa pool heaters.

It’s an enticing pool replacement part given its role in stabilizing the high limit temperature switches. If you want to maximize the bang of your bucks, then you should seriously consider Pentair 42001-0053S.

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6. Pentair 460736 Master Temp

No products found.

If warming up your pool feels like an eternity, fret not. Gas-fired swimming pool heaters strike the right cord. And as long as you are willing to meet the premium costs of acquiring the Pentair 460736, then you are all set.

Pentair 460736 Master Temp can be a life-saving supplement to its cost-competitive alternatives when the vagaries of the weather take their course.

Also, it makes good sense to have the best pool heaters for in-ground pools in an area where propane or natural gas is available. And if your budget allows, you can rely on the 120-pound model regularly, although this option isn’t always feasible, given the spiraling fuel costs.

The 460736’s rating is high, at 400,000 Btus. But you will have to fork out large sums for such an output.

Unsurprisingly, Pentair’s popular because it gives you value for your money and helps to reduce whining in your household, although you will have to contend with high gas bills, which can blow your budget.

It can raise 1-1/4 degrees Fahrenheit every 60 minutes, and the potential increases for a higher Btu-rated in-ground pool heater. Despite impressive output, the devices of Pentair’s caliber are less efficient than solar and heat pump models.

Sure, you will need a bulk tank. Else, you will have to deal with the costs of replacing a smaller tank. The model also emits toxic gases like nitrogen oxide and carbon monoxide.

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7. Smart pool EQTM2400NA Programmable Timer

Smart pool EQTM2400NA Programmable Timer
246 Reviews
Smart pool EQTM2400NA Programmable Timer
  • 5 hour cycle options
  • One touch operation
  • Built in supports for mounting, along with a clear protective cover
  • Single 15 amp outlet
  • 2' electric cord

The Smart Pool EQTM2400NA is inexpensive and is easy to install. You don’t need professional help to install. It’s a small and lightweight device, at just 0.8-pounds.

Yet, this gadget, however small, can do big things. The pool timer can prevent time and money losses. It saves you from the hassles of having to set the timer yourself and waiting for time to elapse to turn on the pump.

We tend to forget, and we are always busy. With the pool timer for the best pool heater at your disposal, you can go on with other errands without having to worry about switching the pump.

The last thing you want is to come from a long sabbatical to a green pool full of algae. Hence, Smart Pool is invaluable. It turns the pump on or off after every five hours (five-hour cycle).

But this is an option, as the pool pump timer allows you to automate jobs for times you have specified. You can connect it to your smartphone through an app.

And so, when you are not always at home, the EQTM2400NA is a real deal. Also, when you want to delay switching between the pump and the heater, the EQTM2400NA coordinates it.

Such coordination prevents the pool from becoming too hot, resulting in pipes pounding and knocking, which can reduce the efficiency of the pool heater.

Smart Pool also bestowed on the gadget protection from elements. If you aren’t tech-savvy, unfortunately, SmartPool isn’t for you. Ensure the specs of your smart pool timer and pump match.

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8. Smart Pool S601 Pool Solar Heaters

Smart Pool S601 Pool Solar Heaters
  • Keep your pool warm with a polypropylene heat collector. Direct Flow System - One Header Hole for Each Heating Tube
  • Solar heater features 80 square feet of solar panels
  • Pool accessory is perfect for heating any in-ground swimming pool
  • Panel array measures 4 feet wide x 20 feet long. Raises Pool Water Temperature 6-10°F (4-6°C)
  • Installation kit required (Sold Separately)

Smart Pool S601 is a single panel, although you are likely to need more sun’s rays collectors if you have a larger-gallon-capacity swimming pool. The collector system has no glazing (glass covering).

Instead, a UV-treated polypropylene makes up the solar panels. These parts are rather cost-friendly and are simple, although they can’t effectively pick up solar energy when chilly weather sets in.

When you want to determine how many panels you need, you need to size your pool. The S601 is the best pool heater if you have an investment mindset.

Don’t let upfront installation costs discourage you because it will take between 1-1/2- and 7-years to recoup your money. And no gas-fired and heat pump pool heater is more durable than the solar model. However, not every home’s situation is amenable to solar panels.

If a shady environment surrounds your home, then you’ll need to clear it. Also, if the roof area is smaller than the panel area, you will have to incur the extra hassle and costs of putting up mounts, which may be inconvenient.

Unless the sun holds out, the S601 isn’t a practical alternative. Besides, when a series of cloudy days occurs, you may not be able to achieve a comfortable temperature.

All-in-all, your swimming pleasure is always at the mercy of the moody weather if you don’t have a backup heating plan. Be sure to check for rebates from the local and federal governments.

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9. Hayward HP21404T Heat Pro

Hayward HP21404T Heat Pro
146 Reviews
Hayward HP21404T Heat Pro
  • Acoustic compressor cover and profiled fan blade ensures quiet operation and efficient performance
  • Ultra-Gold corrosion resistant evaporator fin for extreme durability especially in coastal environments
  • Titanium heat exchanger designed for maximum heat transfer, efficiency and reliability
  • Durable injection molded UV-resistant body panels that are impervious to rust and deterioration
  • 2in x 2 1/2in CPVC Union Plumbing Connections - Common union for installation or service, adapts to larger plumbing recommended for greater efficiencies

This 287-pound pool heater draws electric power to transfer heat. It doesn’t produce heat. Instead, it works by harnessing heat from hotter to colder environments.

As long as the outdoor temperatures lie between 45- and 50-degrees Fahrenheit, the HP21404T will be efficient. Cooler outdoors temperatures don’t play in favor of any heat pump pool heater, as it will require more energy input to achieve a proportional output.

However, chilliness and power consumption shouldn’t be a problem if you want to swim in warmer weather. While the Hayward is more efficient and longer-lasting than any gas swimming pool heater you will encounter in any pool heater review, it’s costlier.

Hence, if you approach the best pool heater for utilizing energy input and maintaining low operating expenses with an investor mindset, then the HP21404T is the right fit. Also, you must determine the size of your pool heater, as it affects the heating load.

Sizing takes into account the pool surface area, the difference between atmospheric and water temperatures, cold nights, humidity, and wind. Hayward’s rating is 140,000 Btus, and peak horsepower is 6hp and thereabouts.

These numbers are decent. You can expect your pool to warm up by between 1- and 1-1/4-degrees Fahrenheit per hour when the wind speed is not more than 3-1/2-miles per hour.

When it comes to efficiency, the heat pump pool heater is the king. With a coefficient of performance (COP) ranging between 3.0 and 7.0, the HP21404T gives an output that is between three and seven times the energy the heater requires to produce it.

Hence, it’s a cost-effective alternative to furnaces and gas pool heaters.

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10. Hayward CSPAXI11 11 Kilowatt Electric Spa Heater

Hayward CSPAXI11 11 Kilowatt Electric Spa Heater
  • Heater on indicator light
  • 304 stainless steel tank
  • 304 stainless steel threaded head, safety sensor electric heating element
  • Service-ease design gives simple access to internal controls

This 11kW-capacity electric heater befits small pools, spas, and hot tubs. Initially, you will pay less to install the electric in-ground pool heater than the gas-powered model.

You can fit the 12.17-pound electric swimming pool heaters into a small space. As such, they don’t consume much room. Therefore, you can place the swimming pool heaters indoors.

However, electric models are more expensive when costs spread over the long-term. It would cost you an arm and a leg to run the devices.

If you hope to gain savings, you won’t. If you close the thermostat to save power when you go to sleep, you are likely to walk into a chilly pool the following day.

While it would be a breeze to trap heat from the atmosphere during the warm months, operation costs will escalate during winter, as the electric equipment will require lots of energy to extract heat from the cold air.

Depending on the coefficient of performance (COP), Hayward can give out heat amounts that are multiple times greater than the energy the model consumed.

Also, if you are looking for a versatile pool heater, then the CSPAXI11 it is. You can adapt the best pool heater for various weather conditions to extend the swimming season.

Electric heaters also take a long period to warm up your pool – it’s easy to lose patience. You will reap maximum benefits with the Hayward CSPAXI11 when air temperatures are above 45 degrees Fahrenheit.

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11. Fibro Pool FH055 In Ground Swimming Pool Heater

Fibro Pool FH055 In Ground Swimming Pool Heater
  • 100% Titanium heat exchanger
  • Quick disconnect piping, 1 1/2" pvc and 17 Amps power-220 volts
  • Digital display and controller
  • 16" x 40" footprint, slim fit
  • US Department of Energy top Energy Efficient System, 25 cents per hour

This heavy-duty model weighs 120-pounds. And with an electric item of its caliber at your disposal, toxic emissions should be the least of your worries, unlike the case with the gas pool heaters.

While many electric swimming pool heaters may not be nearly as efficient as heat pumps, the FH055 is an exception to the rule. The model is worthy of consideration, given its decent output, which rates at 55,000 Btus.

Also, its COP rating is mouthwatering, at 5.92, which translates to a staggering efficiency of 592%! Fibro Pool releases about six times as much the energy it needed to produce the output.

However, at its hp (Btu), it may take a couple of hours for your pool to achieve the high 70s. It’s among the most efficient heating devices you will come across in any pool heater review.

Its initial cost is thousands of dollars more budget-friendly than the heat pump and solar models, but you will have to contend with monthly electricity bills.

But given its proper utilization of electric energy, the FH055 is worth every cent.

Unless a power outage occurs, the Fibro Pool remains the best pool heater for anyone who looks to offset high energy bills and has a backup generator or something.

And because the pool water loses water at a much slower than the atmosphere, chilly weather shouldn’t be an issue.

You can swim in the early morning and cold nights, as long as you have waited for your pool to get sufficiently warm.

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12. Eco Smart SMART POOL 27 Electric Tank less Pool Heater

Eco Smart SMART POOL 27 Electric Tank less Pool Heater
151 Reviews
Eco Smart SMART POOL 27 Electric Tank less Pool Heater
  • Flow Activation
  • Eco smart Pool Heaters are compact and easy to install for a new or existing pool
  • Set your temperature digitally to increments of 1-Degree. Set it and forget it.
  • Compatible with Eco smart Remote Control. Activation Flow - 12 +/- 2 GPM
  • Can be used as an alternative to or booster to heat pump.

If you are looking for the maximum bang on your bucks, then the 27kW-capacity model is a smart option.

Eco Smart is a lifesaver when you feel you can no longer put up with fuel-guzzling furnaces and costly central heating and cooling systems.

While heat pumps are more fuel-efficient than electric heaters, you won’t have to worry about a dip in performance when temperatures hit below 45 degrees Fahrenheit.

Nor would you have to invest in costly backups. While a device that raises pool water temperatures by a couple of degrees demands lots of patience, you benefit from stability.

You won’t have to contend with outrageous utility bills that spring up from time to time. If you are comfortable with technology, Smart Pool 27 will enthuse you.

With electric heaters, the risks of exposure to harmful gaseous emissions are minimal. At 24.2-pounds, Eco Smart is lighter than its counterparts that are usually heavier and bulkier.

The price is also budget-friendly for anyone who looks for a portable device that serves household needs.

The best pool heater usually comes with a pressure sensor to prevent flowing water from pounding and knocking and hence damaging the parts of the pump.

The device’s flow sensor technology enables it to last long. It’s a device any tech-savvy buyer will find joy in using.

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Buying Guide: What to Consider When Select Pool Heater

Swimming pool heaters are long-term investments. When you maintain them well, they can last for decades. They are usually expensive to install. Let’s examine the factors you need to consider before you make the ultimate decision.


You are likely to encounter electric, gas, and solar models. Electric models are the most efficient. Gas- and electric-powered leave bills. But fuel bills can rise or fall.

However, it’s not fun to keep paying skyrocketing bills. Solar energy is free, but the installation costs are high. You also need to clear shade and tilt and orient the panels to increase efficiency.


The most efficient water heating devices give more energy than they consume. Electric swimming pool heaters like the heat pump are highly efficient.

The efficiency of solar-powered swimming pool heaters depends on how you orient the panels to the south and on how you have tilted them to the latitude.

The gas pool heaters have the highest horsepower (Btus) and will warm up your pool in no time, but they give high bills.

Pool Size

The capacity of the pool determines whether your pool heater will raise a single temperature by a single.

Larger Btus are overkill, but smaller Btus leave water as chilly as it was. Hence, size your pool before you choose the best pool heater for your purposes.

Also, take humidity, wind speed, differences in temperature between the air and the water, coveted rise in temperature, and cold nights into account. You will need to know lots of math to calculate the heat.


In this pool heater review, you have gained some super-useful tips on how to select the best pool heater. In a market with a flurry of options, fuel efficiency is the king.

Utility bills can increase or decrease, depending on the price behavior of fuel. Even electricity relies on fossil fuels. Solar energy is a viable option, as long as your pool’s location is shade-free.

Sunlight is free, but the installation costs are high. However, high utility bills aren’t friendly to your pocket. Weather is another important factor. Heat pumps and gas-fired pool heaters are vulnerable to weather changes.

When choosing, ensure your choice is invulnerable to the elements and price changes. Unfortunately, none isn’t. And so, select an option that either eliminates or reduces the bills.


  1. https://www.thespruce.com/best-pool-heaters-4689435
  2. https://www.toptenreviews.com/best-pool-heaters
  3. https://www.popularmechanics.com/home/g35880107/best-pool-heaters/
  4. https://www.swimuniversity.com/pool-heater/

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