With the AOS cut, the optic will sit as low as a slide with a dedicated Optic Cut. This allows the end user to have a greater selection of Iron Sights, they will not require sights for a specific Modular optic system. 

The adapter plate features a locking tab, center rib and 3 set screws. Not only is the adapter plate more robust, the adapter plates are precisely machined for each optic. All these factors provide a secure mounting system and a system that will retain zero during re-installation.

This model of the Agency Arms AOS features a cutout for the Rear Sight Behind the Optic.