These are our most popular AASHTO M-247 Standard DOT reflective glass beads for road marking projects! The Type 1 beads have a sand like texture. These are the same reflective glass beads used on highway, state and interstate traffic lines. Meet all Federal and State specifications. Inter-mix(for texture) or drop on(makes reflective) applications. Bead size: Range from 20-325 US Mesh, 45-850 Microns Roundness >= 80%. Refractive index is >= 1.51.