CGW Cut-Off Wheel, High Speed Premium Straight, 4 in Wheel Dia, 1/8 in Wheel Thickness, 1/4 in Center Hole, 24 Grit, Coarse Grade, Aluminum Oxide Abrasive, 22000 rpm Maximum, Resin Bond, Applicable Materials: Metal and Steel, Wheel Type Number: Type 1, Wheel Hardness: R, For Use With: Die Grinders, Yes Reinforced.