Description Reviews The 9mm caliber brings a lot of good things to the AR platform. It has an ability to go off of mags you probably already have, and is light on the barrel as well. It is an accurate and powerful cartridge that lends itself well to the gas system of the AR. The product specs: 9mm Upper Receiver 7.5″ Phosphate Barrel 9mm 1×10 Twist 9MM BCG 7″ Keymod Rail Flash Hider Thread – 1/2″ x 36 9 mm 80% Lower Receiver Lower Parts Kit Stock Kit Assembly Compatible with Glock Magazines Made in the USA Where Can’t we ship? : Shipping to New Jersey, New York, Hawaii, Connecticut, Rhode Island and Washington D.C. is not possible due to state regulations against 80% lowers.