The Bosch HVAC 8733906131 Control-Unit UPM II Double Stage Kit is a replacement control component designed to manage two-stage operation in compatible Bosch HVAC equipment. It processes system signals and coordinates heating or cooling stages according to operating demands, helping maintain accurate temperature control and efficient performance. This control unit is used in compatible... https://www.partshnc.com/bosch-hvac-8733906131-control-unit-upm-ii-double-stage-kit