EOTech quick-disconnect ring mounts are designed to mount your riflescope onto an AR-15 style rifle with a MIL-STD-1913 rail. Also, the 2 inches cantilevered offset positions the riflescope in a forward position. It is providing the correct eye relief and head placement. Besides, the EOTech Cantilever Ring Mount positions the center of the riflescope tube at 37mm (1.46″) above the top surface of the Picatinny base.