FlexOvit® High Performance™ Cut-off Wheel, Depressed Center, 4-1/2 in Wheel dia, 1/8 in Wheel Thickness, 7/8 in Center Hole, A30S Grit, Aluminum Oxide Abrasive, 13300 RPM Maximum, Applicable Materials: Hard Alloy, Metals and Stainless, Wheel Type Number: Type 27, For Use with: Angle Grinder. FlexOvit® High Performance™ A0736 Depressed Center Cut-Off Wheel, 4-1/2 in dia x 1/8 in Thick, 7/8 in Center Hole, A30S Grit