Pentair 074451 Heat Exchanger Assembly Replacement MiniMax and PowerMax Pool/Spa Heater Heat exchanger assembly replacement Fits Pentair MiniMax Plus pool and spa heater model 250 Also fits Pentair PowerMax pool and spa heater model 250 Assembly without heads This products weights 25 pounds; measures 18-3/4-inch length by 3-inch height by 14-3/4-inch width