This is for one FN Cage Code marked barrel assembly in New take-off condition meaning that they were removed from new M16A4 rifles showing evidence of factory test firing and handling marks only. They are marked 3S679 5.56 NATO 1/7. These (20″) barrels are mil-spec 5.56 chrome chamber with 1/7 twist chrome lined bores. They come complete with delta ring assemblies, front sight assemblies, and a gas tube. A great chance to update your rifle or stash a spare set for a future build.