2-Inch(50mm) quick change discs made of aluminum oxide abrasive, high abrasion resistance, fast grinding force and good durability. R-Type Sanding Discs with 3 Specifications: Green Disc: Fine, appr. 400-600 Grit; Red Disc: medium, appr. 150 Grit; Brown Disc: coarse, appr. 120Grit Open nylon web structure with better elasticity and plasticity, suitable for different shapes of various objects, such as stainless steel, alloys, iron, non-ferrous materials. Unique safety torque spiral & Roll lock quick-change design, just twist it to remove or connect, the connection between sanding disc and holder/tray get firmly when rotating. Ideal for surface conditioning and prep, paint and rust removal, sanding, cleaning, grinding, stripping, deburring, polishing, finishing, gasket removal, self-sharpening, scruff blending, and sticker removal and other adhesive removal.