Primary Arms High Cantilever 30MM Mount - Lower 1/3 Cowitness COMPATIBILITY: Will raise most 30mm red dot sights such as Aimpoint, Vortex, Primary Arms, etc. to allow for a lower 1/3rd cowitness. IMPROVED VIEW: The lower 1/3rd cowitnessplaces the red dot in the bottom part of the scope allowing a less obstructed view. LIGHTWEIGHT CONSTRUCTION: Constructed of lightweight aluminum with a hard coat anodized finish and weighing 5.0 ounces.