This is the device that heats an above-ground swimming pool using solar power. Extending your swim season while reducing your pool heating costs, it provides 2,500 BTUs per hour, effectively raising the temperature of a 6,000-gallon pool by 5º F in 10 days. The heater attaches to your pool's pump-operated water filtering system. Water is warmed as it circulates through the heater's coiled, black 20' long heating system that is exposed to the sun's energy, passing back into the pool. Up to four heaters may be linked for faster heating. Includes all hardware and accessories needed for installation. Includes protective cover for off-season storage. 23" L x 23" W x 10" H. (16 lbs.)