Materials: Grain: Auminumn oxide /silicon Carbide/Zirconium oxide Backing: Fiber Coating: Close Application: Idea for removing rust, paint, deburring, polishing welding seam. It 's mainly used for ship, automobile, aviation machinery, bridge, building etc. Features: 1) Should be stored in the dry and ventilating storehouse, avoided moisture and fire, and should be kept in the package before use 2) Storage time: 5 years 3) Available sizes (mm): 230 x 22-40; 180 x 22; 150 x 22; 125 x 22; 115 x 16; 100 x 16 4) Available grit: 16# - 240# 5) Fiber thickness (mm): 0.6 - 1.2