Pentair 77707-0253 Combustion Air Blower Replacement Kit Pool and Spa Natural Gas Heater Combustion air blower replacement kit Fits Pentair MasterTemp pool and spa natural gas heater model 400NA Also fits Pentair Sta-Rite Max-E-Therm pool and spa natural gas heater model 400NA Includes single volt blower adapter Measures 12-inch length by 12-inch width by 12-inch height