PRi 308 Armalite SPR Delta top rail Rifle Length version.  This rail ties the upper receiver to the forearm to create a very rigid shooting platform. This rail will also give you the SPR look in a 308 package.  This rail is constructed of T6 6061 hard coated black anodized aluminum. The rail has a full 1913 rail across the top. Rails come with mounting screws for attachment to forearm rail. Rail is 22" in length.  This Rail is designed to work with PRi's Rifle length Delta forearms.  Mounting this rail requires the 8.5" rail to be removed from forearm.  All mounting hard ware comes with rail.