Advance Rifle Optic & HM3X (Advanced Rifle Optic) is an advancement on our popular 20mm 403 and 503 series optics. Advance Rifle Optic features an all-new 22mm housing design that mates perfectly with our magnifier series and an all-new 1.63” lower 1/3 co-witness pedestal mount. This Advance Rifle Optic-RD2 is available as a 2MOA RED dot only. The HM3X is an aluminum bodied 3X magnifier designed for use in conjunction with a red dot sight. The HM3X is feature-packed and includes a quick release, ambidextrous, flip-to-side Picatinny rail mount. Holosun includes a spacer with the HM3X that provides compatibility with absolute and lower 1/3 co-witness dot heights for maximum compatibility. The HM3X has a generous 2.75” of eye relief, is IP67 certified water resistant, and includes windage and elevation adjustment for precision zeroing to your optic's zero. The HM3X also includes a built-in flat driver tool for easy adjustments.