Colt Cage code upper Pri military latch ch Colt crane spec socom profile barrel Colt F marked fsp Surefire 4 prong Kac ras rail Vero Beach marked rail covers TangoDown grip BCM Bcg Mint upper barrel is a Colt socom chopped barrel. All colt parts minus the bcg. 0 rounds have been put through build. Sadly I have to part ways with this upper.