The M847D is a two position, 24 Vac spring return actuator designed to operate ARD, EARD, and ZD zone dampers. • Low voltage, spring-return damper actuator. • Equipped with anti-rotation and drive shaft extensions for direct mounting to 7/ 16 inch diameter coupling style dampers. • Adjustable range stops. • Direct replacement for M847D1004. Application: Damper Actuator