glass beads made according to international standard include:BS6088,KS and AASHTO, ... transparent ball, no visible bubbles and impurity.Spherical beads:80%(600Sieve size850um,spherical beads 75%)Density:2.4-2.6g/cm3Refractive index ... each is 1000±8kg.3.According to clients' requirement. ) Glass beads for Road Marking AASHTO M247