Thermostat consists of programmable and non-programmable air conditioner and heat pump controls. The units feature non-mercury, non-lead based electronic controls built into a subtle, slim plastic enclosure. Features/Benefits Continuous display back-lighting configurable Auto changeover available Non-volatile memory to retain settings during a power outage Optional battery operation English/Metric units selection Keypad lockout RC/RH power compatible Configurable setpoint limits 3-stage heat/2-stage cool