Designed with medium density polyurethane foam and a tapered edge for conformability, these pads are firm enough for flat surfaces, yet soft enough for severe curves and contours^Available with pressure-sensitive adhesive (vinyl) face in vacuum or non-vacuum^The 6" pads are shock resistant and have a fiberglass backing plate with a riveted 5/16"-24 threaded shank for use on random orbital or dual action sanders^For dual action and random orbital sanders