These Aluminum Oxide sanding belts provide high-speed sanding and finishing in a variety of materials, including wood, plastic, and fiberglass. They can also be used to grind and finish metals and blend welds. Features: Durable aluminum oxide abrasive with an aggressive cutting action. Double-resin bonded to heavyweight cloth. Bi-directional belt splice means no directional arrows to look for. Open coat to reduce clogging when sanding soft woods.