The Resideo HZ221 is a versatile controller for 1-stage heat pump with auxiliary heating and up to two areas of your home where the temperature can be set separately. This unit is compact and measures 8” x 1.86” x 8” and it uses 24V power supply to offer a basic yet efficient way of regulating heat and cool in different areas of the home. #Resideo #HZ221 #HeatPump2-ZoneControlPanel... https://www.partshnc.com/hz221-resideo-1-stg-ht-pumpwauxht-2-zone