Trijicon MRO Quick Release Full Co-Witness Mount with Trijicon Q-LOC Technology mount features a Mil-Spec drop test rated 6061-T6 aluminum design, with a easy to use one handed tool less mounting. Return to Zero features in a low weight, low profile design which works with any Picatinny rail. This means that the MRO is mounted at the same height as the iron sights. The optic’s aiming dot will appear at the top of the iron sight post. This mount is typically used with flip up iron sights.