This Glock 17 Gen4 MOS introduces a revolutionary design that changes to the world’s most popular pistol. Its modular backstrap design lets you instantly customize the grip to adapt to an individual shooter’s hand size. The surface of the frame employs the scientifically designed, real-world-tested, Gen4 rough textured technology. Internally, the dual recoil spring assembly substantially increases the life of the system. A reversible enlarged magazine catch, changeable in seconds, accommodates left or right-handed operators. The Glock Modular Optic System (MOS) simplifies the mounting of popular optics without custom machining of the slide. MOS has four plate options to comply with the specifications of some of the most trusted optic manufacturers in the industry, and a cover plate when no optic is mounted. MOS gives you the option of adding tall iron sights allowing the optic and the iron sights to co-witness.Name : G17 G4 9mm 17+1 4.49 Mos FsDesc : 3-17rd Mags | Accessory RailModel : G17 G4 MOSModel # : PG1750203MOSManufacturer : GLOCKCaliber : 9mmType : Semi-Auto PistolAction : Safe ActionBarrel : 4.49″Capacity : 17+1Finish : Gas NitrideLength : 7.32″Safety : 3 SafetiesSights : FixedStock Frame : Black PolymerMagazine : 3 / 17 rd.Weight : 24 oz.