This 1- Piece Clamp Rigid Shaft Coupling is suitable for applications where alignment is critical and backlash prevention is desired. The coupling wraps around hard or soft shafts without marring. It also features vibration-resistant screws. Use where flexibility is not desired. This listing is for each. Technical Specification Item - Rigid Shaft Couplings Rigid Shaft Coupling Shaft Locking Type - Couplings 1 Piece Clamp System of Measurement Inch Bore Dia. 1 x 1-7/16 Material - Couplings 303 Stainless Steel Finish Bright Outside Dia. 2-5/8 Overall Length 3-7/8 With Keyway / Without Keyway Without Keyway Clearance Dia. 2.84 Screw Size 5/16-24 Max. RPM 4000