The CA-BELT-AL 3 X 21 50G PK10 from Field Tool Supply is an aluminum oxide sanding belt measuring 3 inches by 21 inches, featuring a 50-grit surface for medium sanding tasks. This belt is designed for durability and efficiency, making it suitable for both woodworking and metalworking projects. The aluminum oxide material provides excellent cutting performance, while the pack of 10 ensures you have plenty of belts for extended use. Compatible with various sanding machines, this product is ideal for professionals and hobbyists alike.