Xs shotgun big dot tritium bead on vent rib FEATURES:-Fits shotgun front sight bead of 0.120" to 0.140" on vent rib barrel or either #6 or #26 aftermarket bead recommended. Mossberg factory bead with hex base must be replaced-Epoxies over the factory front bead sight-Front sight only-Enhances sight acquisition in any lighting condition-Low profile snag free design-Excellent in high stress defensive situations-Big dot configuration-Easy installation-Matte black metal finish Other Features: Epoxy over existing #6 bead, requires remington factory size front bead, works with a.125-.140 diameter bead