DEWALT DW4772 4-Inch Grinding Cup Wheel Heavy Material Removal Extended performance diamond matrix provides 350x-feets the life of conventional abrasives and agreeeive material removal Large grinding segments with heat treated steel bodies which provides increases durability and wheel life High-speed 15,000 RPM capabilities, and double row diamond cup design, makes easy work of heavy-duty masonry materials 4-inch diameter; 5/8-inch arbor Includes one grinding wheel