1F83C-11NP White Rodgers

Blue Non-Programmable Digital Thermostat Single Stage 1H/1C Conv. or Heat Pump. Backlit Display, 24 Volts or Millivolt, System Switch-Heat, Off, Cool, Auto, Fan Switch-Auto, On, Horizontal, Dual Power (R-C) And/or Batteries. requires common wire for continuous backlighting.