The truglo starbrite deluxe shotgun sight is our smallest diameter bead replacement endorsed by ducks unlimited.Fiber diameter is.060", fiber length is 0.25".Improves sight acquisition in all light conditions for fast alignment.*note- designed only to be installed on a shotgun barrel with a ventilated or solid rib design.Frame Material: AluminumFrame Color: BlackFirearm Fit: Shotgun w/Vent RibBase Configuration: 5-40Style: BeadFront Material: Fiber OpticFront Color: Red