The UDP-9 Midlength Pistol features a 10.5" barrel. 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 Fire control group: Milspec AR-15/M4 Fire control group. The UDP-9(R) is compatible with most aftermarket 9mm PCC triggers. Please see this page for trigger compatibility 10.5" lightweight profile 9mm barrel in chrome moly with a 1/10 twist, black melonite finish and A2 style flash suppressor Barrel is threaded 1/2x28 and can accept a suppressor B5 Systems pistol grip 10" ultra light skeletonized handguard with M-LOK(R) mounting interface on the 3, 6, & 9 O'clock positions The hand guard features 4 QD swivel mounting points and a top mil-spec 1913 lightening cut picatinny rail with skeletonized M-LOK(R) mounting sections Handguard ID: 1.375* The last 3/4" of the handguard is bored out to 1.405", allowing most aftermarket sound suppressors 1.39" in diameter and smaller to tuck inside of the handguard Top mil-spec 1913 picatinny rail with lightening cut Weight: 5lbs Length: 26? Patent pending Accepts all Glock(R) aftermarket magazines. We recommend using factory Glock(R) magazines. Please see this page for magazine compatibility Includes one 15 or 17 round magazine