045 in Wheel Thickness, 7/8 in Center Hole, Arbor Connector, 46 Grit, Medium Grade, White Aluminum Oxide Abrasive, Wheel Type Number: Type 27, 13300 rpm Maximum, Resin Bond, Applicable Materials: Metal and Stainless Steel, Wheel Hardness: R, Black Wheel.CGW Quickie Cut Depressed Center Wheel, Fast Cut Thin, 4-1/2 in Wheel Diameter, 0.