EGW red dot sights are designed for installation from left to right, with the muzzle oriented forward. The dovetail features a progressive taper to facilitate easier installation. To mount your Vortex Viper/Venom, Burris FastFire or Docter red-dot sight, simply remove the rear sight from your firearm and replace it with the EGW mount. This process requires no modifications and you can remove the mount and reinstall your rear sight at any time. Mounting hardware is included. The EGW Desert Eagle Pre-2017 sight mount facilitates the installation of Vortex Viper/Venom, Burris Fastfire, or Docter red-dot sights without firearm modifications The mount facilitates a swift, reversible installation, including all necessary hardware, and requires no permanent modifications Compatible exclusively with pre-2017 Desert Eagle models, featuring a .187 rear shelf behind the dovetail, unlike post-2017 versions