Fightlite Industries 5.56 NATO 16.25" Black Mag Phosphate. 56 NATO 16.25" Black Mag Phosphate - Complete barrel assembly for use with MCR rifles and upper receiver assemblies. Includes barrel extension with fixed headspace gas block assembly 4 position regulator piston flash hider and dovetail cover. Specifications for FightLite BBL002C 5.56 NATO 16.25" Black Mag Phosphate: Manufacturer: FightLite Finish: Mag Phosphate Additional Features: 1-7in. Twist Length: 16.25 in FightLite BBL002C 5.56 NATO 16.25" Black Mag Phosphate