The Resideo M847D-ZONE Damper Actuator is a spring return actuator that allows for precise control of air zoning in HVAC systems. Operating at 24V, this actuator guarantees that dampers in ARD and ZD zone applications open efficiently as needed. It has a spring return mechanism that restores the damper to its open state, facilitating efficient air distribution and system responsiveness. https://www.partshnc.com/m847d-zone-resideo-24v-sr-open-airzoningdampact