Diamondhead D-45 Diamond Front & Rear Combat Sights - Integrated Sighting System (I.S.S.) (45 degree off-set) - Black Patented diamond-shaped apertures and upper housing for faster target acquisition & centering The rear sight's diamond-shaped upper housing enables fast CQC with apertures flat Proprietary diamond-shaped housing Secure and accurate elevation adjustment Accepts all standard A2 front sight posts Stows like a folding sight For CQC or if optic fails; optics compatible