EA's Intermediate Co-Witness front sight blade designed to work with the new generation of micro red dot sights like the Holosun 507K and the Shield RMS. Both of these Micro Red Dots have integrated rear sight notches in their sight bodies. EA's new Intermediate sight is designed to work with these molded in rear sight body notches. As an added benefit when you remove the red dot and install the DT CAOS filler plate, the rear OEM Five Seven adjustable sight has enough elevation adjustment to compensate for the taller front EA Intermediate blade. This allows you to use the existing iron sights.