14.5 5.56 1/7 twist upper. Bcm extended a2 birdcage ready for pin and weld. Barrel is rosco mid profile 5.56 chromelined 1/7 twist barrel. Aero upper, gas block and tube. Midwest industries combat rail. Under 200 rounds through it, no issues, funding other projects. Located in Killeen text 254-389-4582