Great upper for a super compact package. These uppers allow for a complete folding stock as they do not require a buffer tube to house the recoil system. They can still use any standard AR-15 Lower as well. The upper is chambered in .223 Wyled allowing the use of both 5.56mm and or .223 Selling for $820 CASH FTF in the Corpus Christi area. Call or Text, DO NOT Message on this site, I will not reply!!!! 832-928-1577