Orbital sander pads made from top aluminum oxide grain, durable and anti-static,provides a long lasting grit.Ideal for various materials in both woodworking and metalworking. Open-coat produces an even and consistent scratch pattern,special stearate coating is used to maximize resistance to clogging and pilling,offering better surface finishes,and perfect cleaning and polishing effect. GRIT 40 . Used with 125mm/5 inches sander with velcro hooks. Used for sanding wood, metal, paint, drywall and plastics..