HK 81000625 VP9 Tactical Optic Ready 9mm Luger Caliber with 4.70" Threaded Barrel, 17+1 Capacity, Overall Black Finish, Picatinny Rail Frame, Serrated/Optic Cut Steel Slide & Finger Grooved Interchangeable Backstrap Grip . The VP9 Tactical OR stands out with its 4.7 hammer-forged barrel with threaded muzzle and suppressor-height tritium sights. These sights provide a day or night lower 1/3 co-witness through the window of a red dot sight while remaining visible over the top of most suppressors. Additionally, this model includes an optics cut that, when combined with one of five available adapter plates, accepts most popular red dot sights. Just add the appropriate suppressor and/or optic with no additional modifications needed.