This is a Surplus Air Force contract Capco M16A2 complete upper receiver. I originally bought it for 600 and I'm selling it with full disclosure. It seems to fire and eject ok but I had a lot of failure to feed issues. Someone who is more knowledgeable could probably fix it. It might have just not paired well with the lower, I'm not really sure. My solution was to just buy a new A2 clone and this has been sitting in my safe taking up space for probably 3 years. I'm asking 250 for it. My loss your gain. These are collectable.