Meprolight MEPRO 21 4.3 with Carrying Handle ML62643. These Red Dot Sights made by Meprolight utilize two different illumination systems to maximize target acquisition and provide a proper aiming point. During the day fiber optics light the way and at night a self-powered tritium light glows brightly. The transition between the two lighting systems happens automatically and instantaneously so that you can be prepared for whatever comes your way any time of day. Best of all the Meprolight MEPRO M21 Sight requires no batteries to run as the system is all self-illuminated. Use this sight in any weather conditions and acquire targets at a rapid rate with both eyes open. This is the ultimate CQB optic for military personnel law enforcement and even hunters. Pick up the Meprolight M21 Illuminated Sight and see how a premium grade optic can boost your shooting performance. Specifications for Meprolight M21 Day/Night Self-Illuminated Reflex Sights: Manufacturer: Meprolight Color: Black Magnification: 1 x Objective Lens Diameter: 30 mm Reticle: 4.3 MOA Dot Illumination Type: Fiber Optics/Tritium Illumination Color: Red Emitter Type: Open Parallax: Parallax Free Operating Temperature: -40 - 140 Fahrenheit Water Resistance Level: Submersible Length: 4.48 in Width: 2.16 in Height: 2.75 in Weight: 13.12 oz Condition: New Magnification Type: Fixed Features of: Large field of view (unlimited with both eyes open) Rapid target acquisition Effective use of sight under extreme conditions No batteries. Always ready for action Submersion Unlimited MIL STD-810 Package Contents: Meprolight M21 Day/Night Self-Illuminated Reflex Sights Meprolight 0626232: MEPRO 21 4.3 with Carrying Handle ML62643