The Second Sight series of Aimtech mounting systems for modern rifles is characteristic of Aimtech design work; simple, functional and flawless in execution. These no-nonsense, no-frill mounts are made of a solid bar of heat treated aluminum which has been precisely fitted to the specific rifle and is through drilled down its length with a .375 (3/8) hole which lines up with the rifles existing iron sights. Accepts most Weaver style rings. Allows use of iron sights for close or fast shooting.