Supply PowerMaster model "CH" Industrial Duty Hoist operator for Carwash type applications on Sectional Doors and Rolling Service Doors and Grilles. Primary reduction shall be by heavy duty V-Belt Drive. Secondary reduction shall be a chain and sprocket arrangement. Reduction stages shall be arranged so that mechanism is self locking when torque is applied at output shaft. All reduction shafts shall be a minimum of 1" in diameter, supported by bronze oilite bearings. Operator shall provide an adjustable torque limiting clutch.