The 2A Armament(TM) Aethon Rail M-LOK series provides an alternative aesthetically progressive design that is lightweight with their signature titanium barrel nut and attach method. The innovative attachment of the rail and the barrel nut provides a solid lockup"" a seamless"" strong joint that requires no timed alignment to the barrel nut itself. All 2A Armament rails (and receivers for that matter) are designed with a pocketed picatinny rail to further minimize weight. With new styling and attention to detail the picatinny pockets taper at the end of both the upper receiver and the rail so that one can match the 2A rail to a third party upper if desired and still have a clean transition in the design. In addition"" Aethon rails offer QD mounting at both ends of the handguard.The 2A Armament Aethon and Balios Lite rails ship with a 6AL-4V titanium barrel nut. An optional aluminum barrel nut is offered as a separate item for those looking to save maximum weight on a build.