11.5” 5.56 upper I built but ended up deciding to use the lower for another build. Aero Upper receiver, Aero Kodiak brown Handguard, Ballistic Advantage 11.5” barrel, Sons of Liberty gas block and tube, Q cherry bomb and blast forwarder, Radian Raptor charging handle, Lantac BCG, and Sig Romeo 5 red dot. Fired about 15 times to zero and function check. $450 tyd