3M Scotch-Brite non-woven DF-BL sanding belt uses aluminum oxide as the abrasive material. Since this product is non-woven, Grade is generally used to describe the abrasiveness; with the 64457 having a medium grade. This particular 3M sanding belt is 1/2 in wide by 12 in long. Warning: This product contains chemicals known to the state of California to cause cancer and birth defects or other reproductive harm.