The Spark II is a bead-replacement LitePipe that utilizes the proven HiViz green to achieve instant visibility on any shotgun with a removable front bead, whether plain barrel or vent rib. Fits most vent-ribbed shotguns with removeable front bead. Sight includes five screws in varying thread sizes to fit nearly any shotgun: 3-56"; 5-40"; 6-48"; 3mmx.5"; 3mmx.6".