Honeywell Mercury Free Economy Thermostat, 20-30Vac, 1 Heat, 1 Cool, Conventional Systems and Heat Pumps with No Auxiliary Heat, Vertical Mounting, Heat-Off-Cool System Switching, Auto-On Fan Switching, 45-95 Temperature Setting Range, SPST Switching Action, Manual Changeover, ± 2 Degree Accuracy, Bimetal Sensor Element