Arc Abrasives 71-10807AF Predator Type 29 Flap Discs, 120-Grit, 4-Inch by 5/8-Inch,10-Pack 4 Inch in diameter with a 5/8-inch arbor hole Durable fiberglass backing Angled face at a 10-degree angle to the abrasive surface Max RPMs: 15,150 Pack of 10 flap discs