Diablo 10 pack of 13 320 grit sanding sheets are 9 x 323 Premium 13 sanding sheets include breakthrough innovations that improve performance, extend sanding life and increase productivity Premium aluminum oxide blend a superior quality formulation designed for fast material removal and long sanding life ClogShield, a high performance stearate coating reduces pitch buildup and clogging for maximum productivity EnduraBond, a specialized high strength resin provides superior grittobacking bond for extreme durability