Standard DOT Reflective Glass Beads 50 Pound Bag Size Us Mesh 20 to 325, 40-850 microns Type 1 beads, Refractive index &gt;;1.5 Roundness &gt; =70%. Uses include top of paint paint applications, traffic safety, road marking,art and craft projects. Other uses include art, sand blasting: preening and finishing. Makes paint reflective