001 in, Hub Diameter 2 1/4 in, Hub Material Grade 316.Jaw Coupling Hub, Coupling Size FC25, Outside Diameter 2 1/2 in, Coupling Overall Length 4 1/8 in, System of Measurement Inch, Hub Material Stainless Steel, Maximum Speed 3,450 RPM, Shaft Locking Type Set Screw, Bore Type Solid Bore, Jaw Profile Straight, Bore Tolerance +0.000 in, Shaft Tolerance +0.001/-0.