This will mount the Burris FastFire 3 on a standard frame Glock slide. (G17, 19, etc.) It will remove the rear dovetail as the FastFire is too long to fit between dovetails. Height from top of slide to top of red dot base is .225" so any sights taller than that will be visible through the red dot. Pictured is a Trijicon suppressor height sights at .365" tall, but you will need a new dovetail cut in front of the red dot if you want to add a rear sight. Holes will be tapped 6-48 to match factory provided screws, screws may require fitting for length if you are installing the red dot yourself.