Product Features:Blue ZirconiaDepressed CenterCuts fast and outlasts sanding discs 10-to-1Multiple layers of zirconia cloth flaps constantly expose new extra sharp grinding pointsLaminated by state-of-the art automated equipmentReinforced fiberglass backing plateEach disc is balance tested for vibration-free grinding and finishingWheel Size: 4 inchArbor: 5/8 inch60 gritMax RPM: 15,200
