This new 16" chrome-lined barrel assembly is equipped with a barrel nut, front sight base with bayonet lug and handguard ring. It features an M4 contour, 1 in 9" twist, and phosphate finish. Muzzle end is threaded for 1/2 x 28 TPI flashhiders or muzzlebrakes. Marked: "BFI 5356 NATO 1/19". Note: Front sight post, flashhiders or muzzlebrakes are not included.