Large Diameter Glass Bead Blast Media, #3, 20-30 Mesh Grit, 840-590 Micron Size. 3.6 kg | 8 lbs. Recommended for applications where you want to remove debris without damaging the item's surface. Glass beads are designed to peen surfaces at low pressure. Glass bead media works well on soft metals like aluminum and brass as well as plastic. Glass beads at low pressure will remove substances from surfaces without changing surface dimensions. Works with a blasting gun or in a blast cabinet.