Programmable Thermostat, Customizable Settings

7 day, programmable or non-programmable thermostat, unique function option to customize 7-day & 5/2-day program settings, 2 or 4 periods per day option, keypad lock, temporary override & manual hold, selectable Fahrenheit/Celsius setting, adjustable temperature swing, differential, easy to read back lit display, easy to use, easy installation, battery powered, uses 2 "aa" alkaline batteries, not included, use on most 24v heating & a/c systems, 1 heat/1 cool, gas, oil, electric or single stage heat pump systems, 2 wire heat only hydronic systems, hot water baseboard & radiator, & millivolt systems, wall heaters/furnaces & gas fireplaces.