"The HOLOSUN HM3X-MICRO Magnifier delivers true 3x magnification in a compact package to give your red dot a big performance boost. The flip-to-side QD mount makes transitions fast and easy, while 67mm (2.63"") eye relief provides comfortable viewing. HOLOSUN's premium glass and nitrogen-purged construction keeps it clear and operating in a wide range of conditions. Absolute and lower-1/3 co-witness compatible. True 3x magnification for red dots and reflex sights Flip-to-side QD mount Generour 67mm (2.63"") eye relief Nitrogen-purged Absolute and lower-1/3 co-witness compatible"