Resideo T812C1000 Thermostat

Snap Acting Thermostat, 18-30Vac, 1 Stage Heat, 1 Stage Cool, Conventional Systems, SPST Switching Action, 45-95 Degree Temperature Setting Range, Off-Heat-Cool System Switching, Auto-On Fan Switching, 5-90% RH Operating Humidity Range, ± 3 Degree Accuracy, Snap Action, Premier White, Includes Wallplate, Resistor Assembly, Mounting Screws and Wall Anchors

T812C1000 is the direct replacement for PSM40, PSM40SA