Quick Clamping Shaft Collar, System of Measurement Metric with Inch Bore, Bore Type Round, Bore Diameter 1 1/4 in, Bore Thread Size Not Applicable, Collar Outside Diameter 54 mm, Inside Height to Flat Not Applicable, Collar Width 15 mm, Collar Material Aluminum, Keyway Width Not Applicable, Collar Material Grade 2024, Keyway Depth Not Applicable, Center to Lever Top 40.8 mm, Collar Construction 2-Piece, Screw Material Stainless Steel, Resistance Properties Corrosion Resistant