3-Wire To 4-Wire Adapter for 24VAC Thermostat Systems With 3-Wire Cable Needing A 4th Conductor

Model 8022 3 to 4 Wire Adapter. In applications where additional wiring cannot be run, the 3 to 4 wire adapter can be used to add a wire to the thermostat. The adapter is also used to fix a broken wire, or add a common wire to a 4-wire system. Includes 3 to 4 wire adapter, Diode 'Y' and 2 wire nuts.