Hayward HeatPro® W3HP21004T In-Ground Heat Pump with Square Platform 90K BTU - The high performance, energy-efficient HeatPro® heat pump quietly and economically maintains the ideal water temperature at all times. It features the industry's only standard ultra gold corrosion resistant evaporator fin which provides extreme durability, especially in coastal environments. The titanium heat exchanger is excellent for salt water and chemical corrosion resistance. Its compact design allows for easy installation and service on new or existing pools.