5-2 day or 1 week programmable thermostat, 750 millivolt, large backlit display shows current room temperature & set point temperature simultaneously, smart response learning learns your heating/cooling cycle times to deliver the right temperature when you want it, auto change from heat to cool includes change reminders for filters & low batteries, temporary & permanent hold settings, real time clock automatically adjusts for daylight saving time, program is retained in memory in the event of a power outage, 12 or 24 hour time display fahrenheit or celsius temperature display, short cycle protection, single & multistage heating & cooling, also heating only, cooling only, furnace warm air, central air conditioning, heat pump without auxiliary heat, heat pump with auxiliary heat, hot water, steam or gravity, 750 millivolt gas fireplace, 24v electric baseboard heat.