Depressed Center -Off Wheel, Abrasive Material Aluminum Oxide, Connector Size 7/8 in, Connector Type Unthreaded Hole, Grit 60, Overall Diameter 4 1/2 in, Overall Thickness 0.045 in, Primary Material Applicationn Aluminum, Brass, Cast Iron, Copper, Stainless Steel, Steel, Compatible Tool Type Angle Grinder, Series The Ultimate , Wheel Type Type 27, Maximum Operating Speed 13,300 RPM, Grade Medium