Gator, 5 Pack, 3 x 21, Aluminum Oxide, Sanding Belts Assorted, Designed For Heavy Duty Sanding Grinding Of Wood, Metal, Fiberglass Painted Surfaces, For Use On Power Belt Sanders, BiDirectional Flush Joint Allows The Sanding Belt To Run Smoothly In Both Directions, Resin Bonding System Resists Heat Humidity, Extending The Life Of The Sanding Belt, Made Of Heavy Extra Weight Cloth For Maximum Strength