... photos 2,Safe,reliable andstrong warning function . Glass road stud anti-impaction capacity:>20 ton weathering resistance properies:>16280h ... , the surface was hemispherical, 360 ° full-reflector, reflective no dead ends; brightness reaches the national standard, the ... coefficient 80mcd/LX above; high strength, consistence brightness, reflective effect, long-life; the surface is made by grinding ...