Jaw Coupling Hub, Coupling Size MJC19, Outside Diameter 19.1 mm, Coupling Overall Length 27.2 mm, System of Measurement Metric, Hub Material Aluminum, Maximum Speed 8,000 RPM, Keyway Depth Not Applicable, Keyway Width Not Applicable, Bore Diameter 8 mm, Shaft Locking Type Clamp On, Bore Type Round Bore, Jaw Profile Curved, Screw Thread Size M2.5, Bore Tolerance +0.05/-0.00 mm, Fail Safe Yes, Shaft Tolerance +0.000/-0.013 mm, Full Bearing Support Required Yes, Hub Diameter 19.1 mm This product contains a chemical that is regulated under California Proposition 65. Warning: This product contains a chemical known to the State of California to cause cancer. Warning: This product contains a chemical known to the State of California to cause birth defects or other reproductive harm. -