This mount is incompatible with any optics-ready Sig models. 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. The mount can be removed and the rear sight reinstalled at any time. Mounting hardware is included. The EGW mount is engineered to substitute the rear sight on Sig Sauer models, facilitating the attachment of Vortex Viper/Venom, Burris Fastfire, or Docter red-dot sights The mount is incompatible with optics ready Sig models, including Sig 1911s, P210 Target, P365, and FN 509 Tactical The package contains mounting hardware and necessitates a 5/64 inches Allen wrench for installation; professional installation by a gunsmith is advised