This Bobro Trijicon MRO Mount provides a lower 1/3rd co-witness, when mounted on the AR15/M16 weapons with attached front sights. It features the patent pending BLAC lever system which requires no manual adjustment to attain a proper, rock solid engagement on a 1913 Picatinny rail, and unlike other popular high-end mounts this one won't did into your rail. The system is modular and can utilize offset risers as well as cantilevered risers. The riser features rear and sides serrations to minimize glare. Like all BLAC mounts, the lever can be mounted any side or direction. When just using the low base, lever can only be used on the left side. The Bobro Trijicon MRO Mount comes with all tools necessary for installation.