Meprolight MEPRO M21 Open X Red Dot Sight with Carrying Handle Black ML62663. It is specifically unique in that no batteries are needed. Illumination of the point of aim reticle is achieved by a fiber optic collector system during the day and by a miniature self- powered tritium light source at night. A large 30mm display window allows the shooter to keep both eyes open for better battlefield situational awareness. The shooter has the option of five reticles - 4.3 MOA dot or 5.5 MOA Triangle Bullseye and X. Day or night no matter the weather conditions with the M 21 it is always on and always ready. With Meprolight Everything You Aim For. MEPRO M21 is the reliable choice. Designed and manufactured the highest military standards to assure years of reliable operation under all field conditions. With no switches no battery or other external sources of power these Red Dot Sights are always ready for action. Specifications for Meprolight MEPRO M21 Open X Red Dot Sight with Carrying Handle: Manufacturer: Meprolight Color: Black Magnification: 1 x Reticle: Red Dot Emitter Type: Open Included Accessories: Carrying Handle Condition: New Magnification Type: Fixed Red Dot Sights-Footprint: Aim Point Acro Features: Large field of view. Quick shooting in urban areas. Rapid target acquisition. Always available with no loss of power. Operates under all weather temperature conditions. Package Contents: Meprolight MEPRO M21 Open X Red Dot Sight with Carrying Handle Meprolight 0626632: MEPRO M21 Open X Red Dot Sight with Carrying Handle Black ML62663