It's a Aero precision Upper faxon barrel and matched gas system. Free float handguard. Standard bcg and ch. Cool brake!! Lower is a spikes crusader lower. Ambi short throw safety selector, magpul furnature, geiselle trigger, Shoots ultra soft and smooth. The lower was 500 alone with that trigger and upgrades and I have about 725 in the upper. Includes folding angled iron sights and Aimpoint Pro optical.