Features (high refractive index glass beads): 1) Shape: spherical 2) Color: white 3) Specify gravity: 4.1?.1g/cm3 4) Opacity: 5.0% 5) Roundness: 95% (min.) 6) Refractive index: 1.9-1.93 7) Size: 20 - 30 / 25 - 37 / 35 - 45 / 45 - 55 / 53 - 65 / 60 - 75 / 75 - 90 / 90-150um 8) Various other sizes available Packing: 25kg/iron drum suitable for exportation