If you want the ultimate in co-witness with the EOTech Unit and you have a flat top receiver on your AR. It is the Rock River Arms Dominator II Rail and rear sight assembly. It was designed for the DEA and the FBI and all of the Government Agencies that were on the DEA Contract. I will explain how it works and what it does as brief as I can. The unit is a rail with a rear sight that sets right on you flat top! Once you install the unit just sight in the iron sights. Then mount your EOTech on the Dominator Rail. Once mounted turn the EOTech on. Then look through your iron sights and dial the reticle on the EOTech down on top of your front sight and in the center. You then need to make "maybe?" a very slight adjustment to finalize zero on the EOTech. Once a Zero has been achieved with your iron sights and the EOTech you no longer have to use the iron sights. You simply look about a quarter of an inch over the top of your iron sights at the EOTech Reticle ONLY! That way the iron sights are no longer visible when sighting the rifle on target. But since I told you earlier that you sighted the EOTech in using the pre sighted Iron Sights it is for the purpose if the optics ever should fail. In that case all you need to do if that happens is drop your head *one quarter of an inch while looking through the EOTech Screen at your front and rear iron sight and you have automatically co-witnessed and are on target. No need to perform a fine motor skill of flipping up iron sights when fine motor skills go away in a critical situation. Not to mention the total dangerous transition time of needing to move and get flip ups sights up. The other thing the Dominator accomplishes is not having your eye trying to focus on one sight when the other sight/s are present and in view.
Finally NO you do not have to co-witness if you use an EOTech some choose to not have iron sights. But most law enforcement agencies have a set rule if you have optics the iron sights must be readily available!
Last edited by Sniper03; 12-29-2011 at 10:43 PM.