The Braeburn 1230 non-programmable thermostat is 4.25” high x 5.12” wide x 1” deep, powered with either 24 Volt AC or with two “AA” Alkaline batteries (3.0 Volt DC). In the event of a power failure, the unit will retain all user, installer settings and setpoints. The thermostat is compatible with low voltage single or multi-stage gas, oil, or electric heating or cooling systems, and single stage heat pumps with or without auxiliary heat. Also compatible with 250mv – 750mv millivolt heating only systems and 2 wire hydronic zone systems. The thermostat has a bright blue backlight display and separate sub-base. Temperature control range is between 45 and 90F (7 and 32C), accuracy of /- 1F ( /- .5C) and operating humidity range between 5% and 95% relative humidity. The thermostat includes separate installer and user setup modes, heat pump check terminal, permanent non-volatile memory to retain user settings, filter check monitor and installer lock mode.