... high refractive index glass over 1.93. upgrade runway safe level. Airport Runway Marking Lines Glass BeadsRoad Marking Glass BeadsHigh-Refraction Reflective ... , reflective signs, advertising materials, clothing materials, the standard field runway, shoes, hats, bags, life-saving supplies and so on. ... 25kg/barrel, Gross Weight: 26kg/barrel (Volume: 23cm * 23cm * 32cm). airport runway glass beads