Quick Clamping Shaft Collar, System of Measurement Metric, Bore Type Round, Bore Diameter 30 mm, Bore Thread Size Not Applicable, Collar Outside Diameter 54 mm, Inside Height to Flat Not Applicable, Collar Width 15 mm, Collar Material Carbon Steel, Keyway Width Not Applicable, Collar Material Grade 1215, Keyway Depth Not Applicable, Center to Lever Top 40.8 mm, Collar Construction 2-Piece, Screw Material Stainless Steel, Resistance Properties Corrosion Resistant, Screw Seating Torque 16 N-m