This is double output shaft for NMRV30 Worm Gear Speed Reducer, the output shaft diameter is 14mm with 5mm keyway and M6 screw holes on both ends.Manufacturer Part Number: RV30-ABSingle/Double Shaft: Double ShaftOutput Shaft Type: Key WayOutput Shaft Diameter: Φ14mmOutput Shaft Length: 128mmScrew Holes on Shaft End: M6 x 16