Hook and loop sanding discs are used for deburring, blending, cleaning, and finishing on painted surfaces, metal, and fiberglass. The hook and loop system allows discs to be easily removed and reused. A hook and loop backup disc pad is required and is sold separately. Discs can have a cloth, film, or paper backing. They may be solid or contain vacuum holes for dust removal. Common abrasive materials include aluminum oxide, ceramic, silicon carbide and diamond. Choose from very coarse to ultrafine grade, or corresponding grit, depending on material being worked and level of precision required.