9 Inch No Hole Abrasive Sanding Discs. Silicon Carbide (S/C). Closed coat, Heavy Y weight Waterproof Cloth backing. High quality and long lasting industrial abrasive waterproof sanding Disc (black colored) work great on automotive applications, auto body paint and finish, solid surface, glass, plastic, fiberglass, marble, tile, leather and non ferrous metals (Aluminum, Copper, Titanium, Nickel). Super Heavy duty Y-wgt material provides extra strength for working with metal. Quality stick on PSA backing with release paper to protect adhesive from contaminates allowing for superior grip. Resin over resin bonding. Anti-clogging stearate (provides a better sanding and cleaner working environment). Wet or Dry applications. Assembled in America.