Aluminum oxide sanding disc for use on wood or metal. Self-Adhesive backing to attach to disc sander. Available Grits: 50, 80, 120, 180, and 240. X weight cloth backed discs - not cheap paper backing. Self-Adhesive is also known as Pressure Sensitive Adhesive (PSA). Resin bond for additional durability. Allow 2 days for manufacturing in USA and shipping.