Shopsmith Aluminum Oxide Sandpaper Discs cut fast, resist build-up, and outlast the competition. These discs are workhorses in the shop, easily handling tough sanding jobs, tool sharpening, and more with superior durability and performance. Made with a durable, open coat Aluminum Oxide (A/O) abrasive that is fast-cutting and resistant to loading for a longer life. Pack Includes (3) 12 Inch 150 Grit Adhesive-Backed A/O Sanding Discs.