Pentair 471694 150-Degrees Fahrenheit Hi-Limit Thermostat Replacement MiniMax Pool and Spa Heater Hi-Limit thermostat replacement Fits Pentair MiniMax NT STD, NT LN, NT TSI pool and spa heater models 200, 250, 300, 400 Also fits Pentair MiniMax CH pool and spa heater models 150 IID, 150, 200, 250, 300, 350, 400 150-Degrees fahrenheit