'Rigid Shaft Coupling, 1 Piece Clamp, Inch, Bore Dia. 1 In., Steel, Finish Black Oxide, Outside Dia. 2-1/16 In., Overall Length 2-1/16 In., With Keyway, Clearance Dia. 2.063 In., Screw Size 1/4 In.-28, Keyway Width 1/4 In., Max. Torque 2470 in.-lb., Max. RPM 4000'