Lay flatter, stick smoother than glue-on type with no glue lumps, giving much longer disc life with no high spots to wear down first. Edges stay down stopping 'catch-and-tear' problems. Much easier and faster to change, with no cleanup between grit changes, and no cleanup of the sander. Special surface, resin bonded to the heavy cloth backing, prevents loading up of disc and drag-off of grit, so stays cutting longer and faster without clogging. For coarse-to-fine metal finishing, and all wood finishing. Sold in packs of 3 discs each.