This is a 14.5" colt socom upper that has been pinned and welded to 16". It is heavy under hand guards, chrome lined, does have the m203 notches, M4 cuts, m4 on front of receiver. keyhole. with charging handle. The upper receiver does not have a cage code or a c mark. Colt did produce some of these with no markings, so take that however. You're pretty much just paying for the barrel.