Meprolight 56225000: Originally developed for the Israel Defense Force (IDF), the Mepro M21 Red Dot Day/Night Self-Illuminated Reflex Sight represents the best of Meprolight tritium technology and remains on active duty for the IDF and militaries and law enforcement worldwide. Dual illuminated 1X Red-Dot reflex sight. Large 30mm diameter lens with Red Triangle Post. Large field of view for rapid target acquisition. The Mepro M21 is suitable for Night Vision Goggles or scopes, including those with GEN III tubes and magnifying scopes, such as the Mepro MX3F/T. Easy positioning of Magnifier close to the sights optics with no decrease in the field-of-view and without compromising convenient switch operation.