There's never been anything like the GTO. GTO/FLX55 fits HK VP9. Custom designed to fit perfectly. The GTO/FLX55 is the most technologically-advanced laser sight available for the HK VP9. Features: GripTouch Activation by using FLXSide-Touch Activation without FLXUltra-bright 635nm red laserFits onto almost any Picatinny Rail U.S. Patents 9,328,994; 10,054,396 Additional Patents Pending Class 3R Laser Product (Does not exceed Class IIIA emission limits), <5mW power output. Custom fit for your pistol model GTO's brilliance comes from over 90 custom-fit FLXs which activate the laser just by gripping your pistol. Matte black, blends into pistol finishVirtually undetectable from the side3M backing, very aggressive & conforming with no harm to pistol finishGold plated touch sensorChemical resistant Easy installation and stays put FLXs are the World's highest-tech remote switches designed to work with GTO & GTO Green lasers. Each FLX is designed specifically for your pistol model. FLXs are barely thicker than a human hair but made from the same ultra-strong, NASA-used polymer that your pistol is made of. Laser can also be activated by touching either GTO side contact with extended trigger finger. If you prefer this activation method, do not install included FLX. GTO shown installed with Finger Touch Adapter (FTA). Laser activates by normally gripping your pistol. No reaching for a switchNo awkward button on the gripFLX allows GTO to turn on instantly Easy to control over windage and elevation Simple laser adjustment with master kill switch for iron-sights practice. Convenient battery door No need to re-adjust laser after battery changes. Made From the Same Material as Polymer Pistols High-impact Dupont Zytel FRN makes every ArmaLaser the toughest laser money can buy.