Besides rails that mount under the gun, In addition there are selections for rails that will allow the mounting of sights and optics. There is certainly the WOR4 Tac Rail that mounts for the entrance of your gun and makes a rail that goes over the top of your slide. https://hectorlapdq.boyblogguide.com/26560400/new-step-by-step-map-for-beretta-92-extended-barrel