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.