The Honeywell MS8120A1205 2-Position Spring Return Direct Coupled Actuator with two auxiliary switches is an HVAC control device that drives dampers or valves between open and closed positions. It uses a direct-coupled mechanism and spring return for reliable operation, with auxiliary switches providing feedback for safety and control logic. https://www.partshnc.com/ms8120a1205-honeywell-24v-dca-sr-2-pos-175-w2aux