C.L. Industries Hydro HYDRODISC50FX7 7'' Diamond Disc Flex 50 Grit . When working with water or air driven tools on marble, quartz or pebble-based finishes, diamond abrasives are the best choice for grinding, sanding, and polishing with ease. Choose from abrasives available in a variety of sizes and rigidity depending on the application and specific job requirements. These abrasives have foam-backing pads with Velcro, allowing operators to change discs quickly and efficiently. Handpads are also available for various jobs or to leave with clients. Lightweight and comfortable, handpads are excellent for small areas and tough to reach places and are offer an efficient and cost effective solution to ordinary sandpaper.