9mm Luger4.09" BarrelPolygonal Bore ProfileNew 17 Round MagazineNew Sight Configuration High Visibility Front / "Clean" Black Serrated RearSpecial Grip Frame with Interchangeable Backstrap Inserts/Lateral PlatesMIL-STD-1913 Picatinny Rail on FrameCorrosion Proof Fiber-Reinforced Polymer FramePatented HK Recoil Reduction SystemOne Piece Machined Slide made from Nitro-Carburized SteelCorrosion Resistant "Hostile Environment" Blued FinishAmbidextrous Slide LeversAmbidextrous Magazine ReleaseMatte Black Finish