This will allow you to mount your Vortex Viper red dot directly to your standard frame Glock without any adapter plates. The Vortex Viper is slightly to long to keep the rear dovetail, without cutting into the safety plunger hole, which we do not encourage. As such, race cut / irons forward is the only option. Since the Viper does not have an integral rear sight, the only way to cowitness with this red dot is by cutting a new dovetail ahead of the red dot. The red dot base is .203" above the top of the slide, so any sights taller than that will be visible through the red dot. Pictured is the Trijicon suppressor height front sight at .365" above the slide. Holes will be tapped 6-32 to match screws included with the red dot, factory screws may require fitting if you are installing the red dot yourself.