Evolution Gun Works Docter Sight Mount for Blank. It will need to be modified to fit in your dovetail. Simply remove the rear sight on your gun and replace it with our mount in order to mount your Vortex Viper/Venom Burris FastFire or Docter red-dot sight. You can take our mount off and replace your rear sight at any time. Mounting hardware included. Installation Instructions: Remove the rear sight Install the EGW Sight Mount in the dovetail Tighten set screw (if applicable) Place the red dot sight on the EGW Sight Mount (placing a small piece of paper between the red dot sight and the sight mount will make for easier removal and will keep Loctite off of the red dot sight.) Apply blue Loctite to the provided mounting screws Torque mounting screws to 15in/lbs 2 Button Head Cap Screws - Provided for Vortex Viper and Venom Sights 2 Flat Head Cap Screws - Provided for Burris FastFire and Docter Sights. The screws that are included with this mount require a 5/64in allen wrench for installation. Specifications for Evolution Gun Works Vortex Viper/Venom Blank Red Dot Sight Mount: Manufacturer: Evolution Gun Works Color: Matte Black Finish: Hard Coat Anodize Gun Make: Glock Fabric/Material: 7075 Aluminum Red Dot Sights-Footprint: Docter Optic Cut: Docter/Noblex Vortex Viper Vortex Venom Burris Fastfire Length: 1.811 in Width: 0.99 in Included Accessories: 2 6-32 Button Head Screws 2 6-32 Flat Head Screws Mount Type: Dovetail Package Contents: Evolution Gun Works Vortex Viper/Venom Blank Red Dot Sight Mount Mounting Hardware Evolution Gun Works 49314: Docter Sight Mount for Blank