The Mirka Hook & Loop sanding discs come on a B weight backing, giving the disc better edge wear & wear ability. The Stearate aluminum oxide grit provides a fast, uniform cut. We stock these discs in 5 hole & 8 hole in the 5" size and 6 hole 6" size. This will cover the most popular sanders on the market. These discs can also be used with a standard pad with no punched holes. (Each size and/or grit sold separately)