9 hp (Hytrel Spider), Keyway Depth 3.7 hp (Buna-N Spider), 5.6 hp (Urethane Spider), 9.3 mm, Keyway Width 12 mm, Bore Diameter 40 mm, Shaft Locking Type Set Screw, Bore Type Round Bore with Keyway, Jaw Profile Straight, Compatible Center Element Manufacturer Part Number L190H, L190N, L190U.