Emerson 1F83H-21PR Heat Pump (2H/1C) Programmable Thermostat Big, clear display - easily read in low lighting Selectable programming - 7 day / 5-1-1 / off Easy installation - built in level indicator, pluggable terminals and streamlined configuration menu Advanced features - keypad lock, temperature limits, backlight button Dual fuel standard - no sensors needed Heat Pump (2H/1C) - Up to 2 stages of heating and 1 stage of cooling Heat only and Cool only Gas, Oil, Electric applications Millivolt and 3-wire zone valve systems