AR15 M16 M4 16" NATO M4 Barrel Assembly includes: 16" NATO M4 Government Contour 1x9 twist, chrome moly barrel, parkerized finish. A2 Flash Hider with crush washer. A2 Sight post, spring & plunger. USGI ruber coated sling swivel with rivit (installed). USGI carbine gas tube with roll pin. M4 handguards with dual heat shields. USGI Aluminum delta ring assembly.Made In USA!