The universal auto changeover thermostat shall be a Braeburn 5020 number 5020, 3.86” high x 5.11” wide x 1.42” 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 shall retain all user, installer and program settings. The thermostat shall be compatible with low voltage single stage gas, oil, or electric heating or cooling systems, and single stage heat pump systems. Also compatible with 250Mv – 750Mv millivolt heating only systems and 2 or 3 wire hydronic zone systems. The thermostat shall have a bright blue backlight display, speedbar, separate sub-base and multi-level keypad lockout. Temperature control range shall be between 45° and 90° F (7° and 32° c), accuracy of +/- 1° F (+/- .5° c) and operating humidity range between 5% and 95% relative humidity. The thermostat shall include separate installer and user setup modes, permanent non-volatile memory to retain user settings, filter, UV and humidifier pad check monitor, adaptive recovery mode (arm), programmable Fan mode, residual cooling Fan delay and indoor or outdoor remote sensor capability. A front reset button will return user settings to default values when pressed. Meets energy aware guidelines.