Hayward CHXTST1930 Thermostat Knob without Knob Replacement for Hayward H-Series Pool Heater Replacement thermostat knob without knob Fits hayward h-series millivolt heater models h1501, h150p1, h2001, h200p1, h2501, h250p1 Also fits hayward h-series pool heater models h100id1, h100idp1 Also fits H-Series CZ and HM2 models Weighs 16 pounds