Jaw Coupling Hub; 4-1/2" Hub Dia; Jaw Coupling; Hub; Shaft; Spline; No Keyway; 5.975" Outside Diameter; 2.31" Length Thru Bore; 600 Size or Series; Set Screw; Magnesium Alloy; 1800 Maximum Speed; Neoprene 4946.7 | Urethane 7420.1 | Hytrel 14840.1In-Lbs Torque