This Pool Heater Will Quickly And Efficiently Introduce Heat To The Water In Pools Up To 15 Feet In Diameter Thanks To Its 2.8Kw Rating. It Can Also Be Used In Even Larger Pools Where It Will Help Take The Edge Off Cold Water To Make Swimming More Comfortable. It'S Extremely Easy To Use And Will Quickly Start To Provide Noticeable Benefits, Warming Pool Water Quickly And Effectively.