Reflective glass beads owns a high index retro reflective property,the principal of the micro structure reflective material is:Light exposure to the object like lens, focus by refraction layer, and then go through the lens from the focal point of to the direction of the light source,form a reflective aluminum layer on the backhemisphere surface of high refractive glass beads,and then >85% of the direct light return to the light source.The retro reflective brightness that the product formed, enable drivers or outdoor workers with light source at night or low-light conditions to identify and take measures to avoid the obstacles as early as possible,so that ensuring safety.