Jaw Coupling Hub; 1-1/4" Bore; 4" Hub Dia; Jaw Coupling; Hub; Shaft; Finished Bore; Keyway; 4.8" Outside Diameter; 1.63" Length Thru Bore; 500 Size or Series; Set Screw; Magnesium Alloy; 1800 Maximum Speed; Neoprene 2194.8 | Urethane 3292.2 | Hytrel 6584.4In-Lbs Torque