The Vortex Optics Impact 4000 GB Ballistic Picatinny Rail Mounted Laser Rangefinder allows you to shoot farther, faster, and more precise. For long-range competitors and open-country hunters, the Impact 4000 is the all-in-one range and ballistic problem solver that delivers point-and-shoot solutions without coming off the gun. This advanced, rail-mounted laser rangefinder provides you with range, ballistic, and weather data via the integrated GeoBallistics solver, on-board Environmental Sensors, and patented Wind Bearing Capture Mode. Intuitive to use. Rugged and reliable. It solidly mounts to any picatinny-style rail or rings with a diving board mount. Best of all, it functions in places your smartphone can’t for deadly speed and precision no matter where you are.