HD107X Mini Slant Window Reflex Red Dot Sight. This ultra-compact 1x open reflex sight is crafted from lightweight aluminum alloy, built with a unique slanted top window design to cut glare and stray light interference for cleaner target acquisition. Equipped with a 22mm objective lens and wide field of view, it delivers unlimited eye relief for fast both-eyes-open aiming. It features 4 reticle styles with adjustable red & green dual illumination, plus auto light sensor brightness control to adapt to all ambient light. Compatible with both 11mm and 22mm rails.