Straightforward display and basic buttons keep operation simple. Backlit display shows current room temperature and set point temperature simultaneously. Plus/minus 1 Deg. F temperature control. Auto change from heat to cool. Includes change reminders for low batteries. Program is retained in memory in the event of a power outage. Fahrenheit or Celsius temperature display. Includes UWP Mounting System, mounting hardware and quick install guide. Requires 2 AA batteries (not included). Compatible with 24-Volt heating and air conditioning systems: single stage and multi-stage heating and cooling, heating only, cooling only, furnace, central air, heat pump with and without auxiliary heat, hot water, steam or gravity, 750 millivolt, gas fireplaces. Not compatible with electric baseboard heat.