Part Number: RZ3-1M 5/16"Shaft Collar, Dowel Pin Length: 1 inch. Please confirm the dimensions before ordering. Voltage: 24 VAC +/- 10%, 60 Hz, 0.36A The WQSING RZ3-1M 24V AC 2-wire spring return damper motor is designed as a direct replacement for M847D series motors. It is compatible with popular ZD and ARD dampers using M847D1004, and M847D1012 models, as well as other M847D motors. This motor can also replace most other brands of 2-wire spring return motors. It works with both normally open and closed installations. Torque rating: 32 in-oz for both powered open and spring closed positions. Torque is consistently delivered across the full 90-degree rotation to open and close the damper, regardless of the actuator's operating mode - energized (power advance) or de-energized (spring return).