The UDP-9 Pistol features a 4.5 barrel and Maxim Defense CQB stabilizing brace. It is chambered in 9mm and fed with GLOCK� magazines. It 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 a matte black hard-coat anodized finish - 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 - 4.5� 9mm barrel in chrome moly with a 1/10 twist black melonite finish and A1 style flash suppressor - Barrel is threaded 1/2�36 and can accept a suppressor - Maxim Defense CQB pistol stabilizing brace with PCC pistol buffer - Magpul K2 pistol grip - Angstadt Arms 4� free float ultra light M-LOK hand guard - Continuous top mil-spec 1913 picatinny rail - Weight: 5lbs - Length: 19 - Patent pending - Accepts all Glock� aftermarket magazines. We recommend using factory Glock� magazines - Includes one 17 round Glock magazine