Pentair 472180 Green Air Pressure Switch Replacement MiniMax Pool and Spa Heater Air pressure switch replacement Fits Pentair MiniMax NT STD, NT STD ASME, Low NOx, Low NOx ASME natural and propane gas pool and spa heater model 250 Also fits Pentair MiniMax NT STD, NT STD ASME, Low NOx, Low NOx ASME natural and propane gas pool and spa heater model 300 Available in green color 0.65 Setting