AEMS CORE X2 enhances the AEMS platform by improving accuracy through an advanced optical system that reduces parallax by 50%. AEMS CORE X2 also features an all-new four post, lower 1/3 co-witness mount. AEMS CORE X2 remains backwards compatible with original AEMS mounts. Features: Solar Failsafe allows the red dot sight to remain powered when your battery fails. 65 MOA Circle & 2 MOA Dot Superled Multilayer Reflective Glass Titanium Housing