Aluminum oxide grain is the preferred choice for woodworkers, and the high-strength resin bond system increases life. These are made with antiload stearate and have high-strength backing for increased durability. They fit DeWalt DW421 and DW423, 5-inch Ryobi, Bosch 3107 and 3725, and Makita B05010 This assortment comes with ten 80-grit 5-inch hook and loop sanding discs, ten 100-grit 5-inch hook and loop sanding discs, ten 120-grit 5-inch hook and loop sanding discs, ten 150-grit 5-inch hook and loop sanding discs, and ten 220-grit 5-inch hook and loop sanding discs.