Installing your red dot sight is simple with EGW mounts. Designed for left-to-right installation while the muzzle faces forward, the mount's tapered dovetail ensures an easy fit. Just remove your rear sight and install the EGW mount to use Vortex Viper/Venom, Burris FastFire or Docter optics. The mount is removable, so you can switch back to the original rear sight anytime. All hardware is included for convenience. The EGW sight mount facilitates the straightforward installation of Vortex Viper/Venom, Burris Fastfire, or Docter red-dot sights on FN FNS and FNX models by replacing the rear sight The package includes mounting hardware, and installation of the provided screws requires a 5/64 inches Allen wrench Constructed from aluminum and available in black, this product is intended for tactical use, installation must be performed by a qualified gunsmith to avoid damage or injury