4x20 Electro Sight Carry handle Scope is specifically designed for M-16 & AR-15 Rifles. Features a built-in bullet drop compensation system calibrated to 500 yards in 100 yards increments. Integrated base that easily mounts on to the inside track of a rifles carry handle at base of the intergrated mount is a peep sight that allows you to use the rifles iron sight.Mil-Dot reticle improved design and fully coated crisp clear optics.