Blue Universal Multi-Stage (2H/2C) Or Heat Pump(4H/2C) 7-Day programmable Digital Thermostat, Backlit Display, 24 Volts, 4 Programs, Automatic Changeover, System Switch-Heat, Off, Cool, Emergency, Auto, Fan Switch-Auto, On, Programmable Fan, Energy Management Recovery, Remote Sense Option, Keypad Lockout, Profile-Horizontal, Tripower (Hardwire, Battery, Battery W/Power Stealing Assist), Range 45-99° F., Terminals-RC,RH,C,G,Y,Y2,W/E,W2,W3,6,O/B,L,+,S,- .