The Siemens Building Technology GVD226.1U is a 2-position, spring-return electric actuator designed to operate fire and smoke dampers in HVAC systems. Operating on 120V AC power, it delivers 200 in-lb of torque to open and close dampers through simple ON/OFF control signals. In the event of power loss or an emergency, its spring-return mechanism automatically drives the damper to its ... https://www.partshnc.com/gvd226-1u-siemens-building-technology-120v-200-sr-2pos-firesmoke