Sanding belt is compatible with portable belt sanders Bi-directional belt splice allows the belt to run in both directions, which simplifies mounting and maximizes sanding life Zirconia alumina grit is self-sharpening, more durable than aluminum oxide, and is recommended for heavy grinding of wood, metal, plastic, and fiberglass Open coat abrasive grains cover 50 to 75 percent of the surface to reduce clogging and promote flexibility for abrading difficult-to-sand materials Cloth backing is more durable and tear-resistant than paper backing, and can withstand repeated flexing