The term “cowitness” refers to the vertical orientation of the iron sights with the aiming point of an optic. When it comes to mounting Aimpoints on AR-15s there are basically two ways to cowitness. Typically, the most common way to cowitness is a lower 1/3rd cowitness. This places the aiming point of the optic slightly above the iron sights for a less cluttered sight picture. The second way to cowitness is an absolute cowitness. This places the aiming point of the optic at the same height as the iron sights.
LaRue has been making lower 1/3rd mounts for the Aimpoint Micros for several years now but they only recently unveiled the LT751 mount which allows for an absolute cowitness. It also features an innovate pedestal design that increase the field of view around the optic and keeps weight to an absolute minimum.
Many people train to use their Aimpoint as a rear aperture sight in the event that their Aimpoint becomes inoperable in the middle of a fight. An absolute cowitness mount like the LT751 can enhance this capability since centering the front sight of an absolute cowitnessed Aimpoint will result in point of impact being closer to point of aim than with a lower 1/3rd cowitness.
This has all the marks of another great mount from LaRue Tactical.