Meprolight USA 626410 M21 Black 1x 30 mm Triangle ReticleOriginally developed for the Israel Defense Force, the Mepro M21 Red Dot Day Night Self Illuminated Reflex Sight represents the best of Meprolight tritium technology and remains in active duty for the IDF, militaries and law enforcement agencies worldwide. A red dot sight with fiber optic illumination by day, Meprolight tritium by night, it provides the advantage on any battlefield with no need for batteries, ever. Its rugged, battle proven