HIVIZ BirdBuster Fiber Optic Shotgun Sight Fits: ventilated ribs from 1/4" to 3/8" width Red in color Made in the USA BirdBuster magnetic shotgun sight Contains 3 frame bases one set of magnets to interchange with different size bases Includes both round and triangular LitePipes in red and green Fits virtually any vent-ribbed shotgun HiViz recommends gunsmith installation for all dovetail sights. Due to manufacturing tolerances, some firearms may require additional fitting.