The FX-9 was designed to be completely modular. Outfit it with any Freedom Ordnance barrel length and customize it with a nearly endless amount of AR-15 accessories. The FX-9 is machined from billet material, anodized type III aluminum components. Steel components are full hard black nitrided including the barrel, bolt, ejector, last round hold open, feed ramp and extractor for extended wear properties and corrosion resistance. Pistol receiver extension installed. All FX-9 models lower receivers are threaded to receive mil-spec buffer tubes. Features AR15 pistol grip; AR15 safety selector; proprietary AR15 style mag release; proprietary AR15 style rear charging handle; free float M-LOK rail and 3 faux suppressor. Mil-Spec buffer tube compatible. Accepts Glock type magazines.