4x20 Electro Sight Carry handle Scope is specifically designed for M-16 & AR-15 Rifles. Features a built-in bullet drop compensation system that is calibrated to 500 yards in 100 yards increments. It has an integrated base that easily mounts on to the inside track of a rifles carry handle. The base of the integrated mount is a peep sight that allows you to use the rifles iron sight. This upgraded model now features a standard black 30/30 reticle, a improved design and fully coated crisp clear optics.