1.supply abiasives since 1999 2. Al2O3 purity 99.6% min 3.Refractory material 4.group sizes ... usually used for sandblasting, such as precious metal, the gold, crystal, the glass and cowboy wear. JIS#280-JIS#4000(1 ... ,5-8mm and 180,200,240,280,320F Super Single Crystal Aluminium Oxide