Ar15a4 Upper Rcvr Assembly, Carbine

Colt Firearms M4 Complete Upper Assembly Only Black .223 Rem / 5.56 11.5-inch

Colt Firearms LE6920CK UPPER KIT 5.56

Colt Firearms LE6921 Upper 556NATO 14.5-inch

Colt Upper 223/556NATO 11.5 Inch Lightweight Barrel w/Integrated Rail

Colt Firearms LE6920CK-NHG Upper Kit Black 5.56NATO/.223Rem 16-inch

Colt Firearms LE6921CK-NHG Upper Kit Black 5.56 NATO 14.5-inch

FN FN15 Upper Assembly 16-inch Carbine