... 5.good quality Features: 1) This series of products are with high intensity, wear-resist, insulative, the surface is smooth ... 20mm x 2.5mm3) Two colors: white and blackAlumina balls,nozzles,substrates have the performances of high purity,good hermetical ... grinding medium for various ceramic material, α-Al2O3 powder, flake alumina, kaolin, fusible corundum,porcelain enamel,dye,ceramic glaze,dope,printing ...