Easy-to-use replacement for standard A2 rear aperture allows the shooter to engage targets at ranges up to 300 yards without changing the aperture, eliminating the need to reposition your head or take hands off weapon. The .095' wide notch at the top of the dual-function aperture face provides point-of-impact zero that lets the operator engage close-range targets with ease by simply shooting to the point of aim like a pistol. Takes the thinking out of the equation for fast, instinctive target acquisition. Use the .070' diameter aperture below the notch for precise long-range target engagement. Flip the CSAT face down to reveal a standard, A2-style .200' diameter peep for close-range only operations. CSAT is easy to zero; even easier to train shooters to use. Zero the notch at 7 yards by aligning the front sight in the notch like a handgun sight, then move back to 100 yards and zero the aperture. Fire test shots sighted through the notch in 5-yard intervals, starting at 10-yards to determine where offset sets in; that’s the range where you should transition to the peep hole. Precision machined from steel, with a serrated rear face that minimizes glare, and a dished area around the peep hole that helps the eye acquire the front sight quickly. Adjusts for windage and elevation just like a standard A2 peep. Developed by Paul Howe, combat shooting trainer and retired U.S. Army assault team leader, sniper, and senior instructor. SPECS: Steel, matte black finish. Fits A2-style AR-15/M16 rear sights.