These 3/4" diameter, fine grit, aluminum oxide (Adalox) discs are manufactured with the grit resin-bonded onto one side of thin, flexible paper-backed discs. (Aluminum oxide is a man-made abrasive that is not as aggressive as Emery and is recommended for use with acrylics, gold and other metals.) Red in color, these discs are long-lasting and water resistant. These discs have the Moore Snap-on brass center so they need to be used with a Snap-on mandrel (see 840-3200, sold separately). Paper backing with one cutting face. Sold in packages of 200 discs.