Depressed Center Grinding Wheel, Abrasive Material Aluminum Oxide, Connector Size 5/8 In.-11, Connector Type Threaded Hole, Grit 36, Overall Diameter 4 1/2 in, Overall Thickness 0.125 in, Primary Material Applicationn Cast Iron, Stainless Steel, Compatible Tool Type Angle Grinder, Series Gemini Flexible, Wheel Type Type 29, Maximum Operating Speed 13,580 RPM, Grade Extra Coarse