The MEPRO M22 PRO Self-Illuminated Reflex Sight with Light Module. The Mepro M22 PRO features a factory-installed light module that eliminates reticle washout and enhances low-light performance. With cutting-edge fiber-optic illumination for daylight visibility and premium Swiss-manufactured tritium vials for nighttime clarity, this sight operates seamlessly in any lighting condition-no batteries required (unless you want it).