Diablo's premium 5 in. 40-Grit universal random orbital sanding (ROS) discs with Hook & Lock backing include break-through innovations that improve performance, extend sanding life and increase productivity. Featuring a premium ceramic blend, these discs remove material faster than other sanding discs and offer an extra long sanding life. Clog-Shield, Diablo's own blend of grinding agents, reduces loading thus maximizing productivity. The superior grain bonding system, Endura-Bond, provides Diablo's sanding discs with longer life and extreme durability.