Venstar ACC0410 Add-A-Wire Kit
In applications where additional wiring cannot be run, the add-a-wire accessory can be used to add a wire to the thermostat. The accessory is also used to fix a broken wire, to make one thermostat work like two, add cooling to a heat only system, or add a common wire to a 4-wire system. made in United States. Manufactured by Venstar.
Product Features
Easy to install
Easier than running new wire
Allows 5 wire thermostats to use only 4 wires
Also allows 5 wires to work like 6 wires