Billet Receivers are 1 shorter than standard AR-15 - Upper and Lower receivers are billet machined aluminum Alloy - Alloy Milspec anodized finish - NEW- 3.5 Freedom M-Lok free float handguard - 4.5 Barrel nitride 4150 Chromoly steel 1:10 twist (1/2x28 t.p.i.) - KAK Shockwave Blade Stabilizer - Fully Heat Treated/Nitride Finish:Enhanced bolt ejector last round bolt hold open feed ramp extractor and charging handle latch - NEW- Handstop (Designed specifically for the FX-9) - AR-15 Configured Last Round Bolt Hold Open - AR-15 Configured Safety Selector - AR-15 Configured Magazine Release - Compatible with 9mm approved 1/2x28 T.P.I. muzzle devices and suppressors - NEW- Anti Walk Pins - Action: Blowback - Length 18.5 - Weight 4.45lbs - Accepts most AR15 Accessories - The FX-9 4.5in 9mm AR Style Pistol uses Glock style magazines with the following updates to our 8 pistol: - Oversized Recurve Enhanced Charging Handle - NEW- Fluted Muzzle Enhancer (1/2x28 T.P.I) - NEW- Custom hand Stop - ETS 31rd Glock Style Magazine included