Honeywell THP9045A1023 Wiresaver Wiring Module for Thermostat Wiring module that connects to "K" terminal on thermostat and separates into Y and G signals to equipment Can be used in conventional and heat pump systems Requiring one wire more than is available Wire Saver for THX9000 Series Thermostats Genuine Honeywell product Wiring module that connects to "K" terminal on thermostat and separates into Y and G signals to equipment Used with THX9000 Series Thermostats Color: Gray, Easy push wire terminals that provide a secure lock with no need to screw in wires. Can be used in conventional and heat pump systems Can be used when 5 wires are needed and only 4 wires are available