Cartridge Roll, Cartridge Roll Design Tapered, Pilot Hole Diameter 1/8 in, Abrasive Material Ceramic, Abrasive Type Coated, Series Blaze R920, Backing Material Cotton, Backing Weight X, Grit 80, Maximum Operating Speed 15,000 RPM, Overall Diameter 3/8 in, Overall Length 1 1/2 in, Grade Coarse