Shaft Collar, System of Measurement Metric with Inch Bore, Bore Type Round, Bore Diameter 15/16 in, Bore Thread Size Not Applicable, Collar Outside Diameter 45 mm, Inside Height to Flat Not Applicable, Clearance Diameter 52.1 mm, Collar Width 15 mm, Collar Material Aluminum, Keyway Width Not Applicable, Collar Material Grade 2024, Keyway Depth Not Applicable, Thread Direction Not Applicable, Center to Lever Top Not Applicable, Collar Construction 2-Piece, Screw Material Stainless Steel