Compact red dot optics are very popular for good reason-- they offer a fast, intuitive aiming solution that works in any lighting condition. This is why the Axeon Optics 7xRGB20 dot sight fills that bill so well. This AAA battery-powered dot sight offers three reticle color choices, red, green, or blue along with 7 brightness levels for each color. With a 20mm objective and ocular lens, this compact model installs on a standard Picatinny rail and securely locks down with a single slotted hex nut.