4 x 21-3/4 sanding belts made from aluminum oxide grain in 120 grit Aluminum Oxide abrasive grain features a Cotton X weight backing Belts feature a butt joint for a consistent and smooth finish and extended belt life Excellent for all purpose sanding Specifically for use on Aluminum, Steel, Composite, Hardwood, and Softwood These 4 Inch x 21-3/4 Inch cloth sanding belts are made with premium German engineered Starcke material. All our belts are made custom to order. This Aluminum Oxide abrasive grain features a Cotton "X" weight backing. These belts feature a butt joint for a consistent and smooth finish and extended belt life. This premium high performance abrasive is excellent for all purpose sanding - and specifically for use on Aluminum, Steel, Composite, Hardwood, and Softwood. 6 belts per pack.