This assembly features a Colt M4 flat top upper receiver with Colt 16inch tactical heavy barrel. This unit was removed from a NIB Colt AR15A3 Tactical carbine so there is no doubt as to who assembled it. Please note the detachable carry handle, charging handle, & bolt/carrier are NOT included. I am not looking for any trades at this time. The price is firm at $499.00 plus shipping. Please contact me via e-mail through the site or direct at CLM4@EV1.NET.