metabo® Depressed Center Wheel, General Purpose, Series: Original Grinding®, 4-1/2 in Wheel Diameter, 1/4 in Wheel Thickness, 7/8 in Center Hole, Arbor Connector, C24N Grit, Coarse Grade, Silicon Carbide Abrasive, Wheel Type Number: Type 27, 13300 rpm Maximum, Resin Bond, Applicable Materials: Concrete, Natural and Artificial Stone, Cast Iron, Ductile Iron, Masonry Materials, Non-Ferrous Metals, Brass and Bronze, Wheel Hardness: N, Yes Reinforced