4", Dry Cut Diamond Wheel, 20 MM, 5/8", 7/8" Arbor, For Cutting Brick, Block & Tile, Fast Shallow Cutting, Matrix Design Minimizes Chipping, Steel Body Delivers Constant Depth Of Cut & Advanced Diamond Matrix For Longer Life & Enhanced Material Removal, Lasts Up To 100 Times Longer Than Abrasive Blades, Used On 4" & 4-1/2" Grinders, Carded.