WEAVER/PICATINNY adjustable sight set for the most popular semi-automatic and pump-action shotguns such as Beretta, Benelli, Remington, Mossberg, Browning, Winchester, Ithaca, etc. The front sight mounts on barrels between .819‘ and .842’ (20.80 mm and 21.40 mm) for standard shotguns and .858‘ and .882’ (21.80 mm and 22.40 mm) for magnum calibres.Base...