Diablo's 3 in. x 21 in. 120-Grit sanding belts include break-through innovations that improve performance, extend sanding life and increase productivity. Featuring a premium zirconium blend, these belts remove material faster than other sanding belts 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 belts with longer life and extreme durability.