VALUE PACK: 40 60 80 120 grit Assorted, 4-1/2" Diameter, 7/8" Arbor, Type #27, 13300RPM maximum speed. HIGH PERFORMANCE: Premium resin-bonded aluminum oxide abrasive produces high performance: durable, good abrasion resistance, anti-static and anti-clogging. Fiberglass backing providing durability and reinforcement. Assorted grit flap discs satisfying all your blending, sanding and finishing requirements from coarse to fine.