SAIT Ovation Attacker Coated Abrasive Flap Disc, Close High Density High Performance, 4-1/2 in Disc Dia, 5/8-11 Center Hole Thread Size, 120 Grit, Fine Grade, Zirconia Alumina Abrasive, Type 27 Flat Disc, X-Weight Fiberglass Backing, 13300 rpm Maximum, Blue