This is our custom built AR-15 204 Ruger upper with Lilja fluted stainless steel 24 inch barrel. 24 inch fluted bull barrel! What you see is what you get! DPMS Upper Low-Pro Competition receiver with Yankee Hills Extreme Tactical Lightweight Forearm. Lilja barrel in 1-12" twist. Lilja has been making match barrels for a long time and have put their expertise in this barrel. We double check head-space after assembly. This barrel will stabilize all 204 bullets up to and including 40 grain. This barrel is one of the best barrels we have ever seen. Hand lapped to perfection. This upper assembly will shoot ½ moa or better with match ammo! Google Lilja! DOES include Les Baer National Match Chromed bolt and carrier assembly, and Tactical charging handle (Better for Optics use). Magazines are the same as 223 or 556. Absolutely no modifications to lower. Will mate to any quality Mil-spec lower except some Colts with the Large diameter takedown pins. We do stock the adapter pins for these Colts.DPMS Low-Pro Slickside Receiver: 7075, T6 aluminum, flattop rail, accepts Weaver-style rings and your tactical accessories. Finished with mil-spec, hard-coat, black anodizing for protection from scratches, mars, and abrasion. We are a FFL licensed manufacturer, but this upper can be shipped to an individual – no need to transfer through FFL. You are responsible to know the laws in your area! DPMS Machined Low-Pro Slickside flattop upper Lilja 1 in 12" twist 20” Stainless Steel Bull barrel Manufactured and Fluted by Lilja Yankee Hill Extreme Tactical forearm Les Baer National Match Chrome carrier assembly with Chrome boltFeel free to ask all the question you have. We take the time to answer them all!