This Mount 1010-AR Riser allows the AR owner to have extra clearance when mounting an optic with a large objective lens. It solidly mounts onto your flat top receiver and allows you to mount your scope on top, via the US Forces 1913 picatinny rail using stanag rings. It has an opening underneath to allow the user to utilize their iron sights if need be. The mount 1010 AR Riser is backed by Osprey’s industry leading no-nonsense lifetime warranty.