A391 Mat Scope Base Allows you to mount your scope on your shotgun; This base is made in a matte black finish; Weaver interface provides a secure fit for your scope; Fits the A400 Xtreme, A391 Xtrema, A304 and A303 Beretta shotguns; Also fits on the A400 Xplor Action shotguns that come with the half moon cutouts on the receiver;