-11, Connector Type Threaded Hole, Grit 36, Overall Diameter 4 1/2 in, Overall Thickness 0.Depressed Center Grinding Wheel, Abrasive Material Ceramic, Connector Size 5/8 In.045 in, Primary Material Applicationn Stainless Steel, Compatible Tool Type Angle Grinder, Series Not Applicable, Wheel Type Type 27, Maximum Operating Speed 13,300 RPM.