Depressed Center Grinding Wheel Abrasive Material Ceramic Connector Size 7/8 in Connector Type Unthreaded Hole Grit 20 Overall Diameter 9 in Overall Thickness 0.25 in Primary Material Applicationn Stainless Steel Steel Compatible Tool Type Angle Grinder Series Quantum 3 SG Wheel Type Type 28 Maximum Operating Speed 6 600 RPM Color Black Grade Extra Coarse