The UDP-9 Rifle is a lightweight 9mm AR-15 rifle. It accepts 9mm double stack GLOCK magazines and features last round bolt hold open. Last round bolt hold open on an empty magazine Flared magwell for faster reloads Integrated oversized trigger guard 7075-T6 billet aluminum lower with your choice of a matte black hard-coat anodized finish Magpul Flat Dark Earth Cerakote or Tactical Grey Cerakote 7075-T6 billet aluminum slick side upper receiver with appropriately sized ejection port and no forward assist or dust cover Threaded bolt catch screw 9mm bolt assembly for use with a standard AR-15 hammer Fire control group: Milspec AR-15/M4 Fire control group. The UDP-9 is compatible with most aftermarket 9mm PCC triggers. 16" 9mm barrel in chrome moly with a 1/10 twist black melonite finish and A2 style flash suppressor Barrel is threaded 1/2A-28 and can accept a suppressor B5 Systems Bravo rifle stock and B5 Systems pistol grip 15" ultralight handguard with M-LOK mounting interface on the 3 6 9 & 12 O'clock positions Weight: 6 lbs Length: 32a ^2 Patent pending Accepts all Glock aftermarket magazines. We recommend using factory GlockA(R) magazines.