3M 3" x 21" 80 grit power sanding belt is designed for portable sanding tools. It features 3M's cubitron abrasive grain and premium aluminum oxide blended minerals on a heavy Y weight cloth backing and film splice, allowing the belt to be run bi-directional, economical and durable. It is suitable for use on wood, plastic and metal. The technology in 3M Precision-Shaped Grain is found in premium 3M Rapid Removal Power Sanding Belts. The 3M Rapid Removal Power Sanding Belts will cut fast and last long during your sanding project. Belts can be used across all stages of sanding, whether you are coating, removing or leveling. Made from premium aluminum oxide grain, these belts cut faster than traditional belts and resist heat buildup and moisture. They are also easy to use.