Truglo's Magnum Gobble-Dot Xtreme easily snaps over rib without need for screws. Endorsed by the National Wild Turkey Federation. *Note- Designed ONLY to be installed on a shotgun barrel with a ventilated or solid rib design. Fits- Browning Maxus, Silver; Charles Daly; Remington 870, 1100, 1187; Traditions Turkey II, Waterfowl II, ALS 2100 Field; Vernona and Weatherby Orion, Athena O/U 12 ga and SA-08 20 ga.