These beads are coated with a special coating materials, during the manufacture of the glass beads,
which will improve the characteristics of moisture-proof and adhesion of glass bead. In the way,
the life cycle of the glass beads can be prolonged and this enhances the beads reflectivity in a rainy night.
These beads are usually used in white or yellow line-construction of highway.
The glass bead can be produced based on the standard of countries or areas,
such as EN1423/1424, AASHTO M247, BS6088, JIS R3301 and KS L2521 etc.