ArmaLite M-15A4 Carbine Upper Receiver. Like new, all factory original. Includes ArmaLite forge marked upper receiver, ArmaLite 5.56 NATO 16" chrome-lined mid-length barrel, ArmaLite marked gas block, ArmaLite bolt carrier group, and ArmaLite mil-spec charging handle. From the Mark Westrom era when ArmaLite was in Geneseo, IL. $390 in League City.