Built with our AAT upper and lower designed for easy takedown and maintenance with us replacing roll pins with set screws to make it easier for you to replace parts when needed, our slick LPK with a nice smooth finish (not gritty like others in the industry) which allows a easy and smooth trigger pull , our Black nitride BCG allowing a smooth glide with no hangups, AAT Luner 6 buffer tube with our design and logo inlaid into the buffer tube with a TF buttstock for comfort during competitive shooting. Also included is our AAT 3.2 Gravity lightweight skeleton grip,AAT takedown pins, our ultra light trigger guard,Our AAT forward assist with our Alien logo standing out showing off the design, Forward Thrust Angled Grip and our Gravity ACH ambidextrous charging handle. This model comes with our 16" 223 wylde 1/7 twist , 4150 CrMov Steel barrel along with our solitary clamp on gas block/yes we eliminated the set screws which always break loose and cause feed problems and in connection with our upgraded gas block comes our carbine length black nitride gas tube with our anti corrosion stainless steel roll pin connecting the two together. We've installed our 14" alignment free handguard/yes NO lining up the handguard with the barrel nut to get it set straight, this design pops right on and tightens down even a child could install and at the end you'll find our pineapple brake which functions flawlessly. Yes everything on a Alien build is Mil-Spec and to top it off we added a Lancer magazine, because why not include a high end magazine with a high end rifle.