The TRUGLO Tru-Bead sight set is a universal sight system for shotguns with vent rib barrels. Fiber optic sights are perfect for low light shooting conditions often encountered while hunting. The front sight features a cnc machined base that houses a red and green dual color fiber optic. The front sight base is attached using the threaded sight bead hole. The rear sight assembly clamps on to the vent rib and includes two rear sight options. One rear sight is a ghost ring aperture with two green fiber optics on the right and left. The second rear sight is a more traditional notch sight with two green fiber optics. The front sight fiber optic is .060" in diameter and the rear fiber optics are .035" in diameter in both rear sights.