Dual-illuminated Fiber optic light collection system Picatinny rail mount included Originally developed for the Israeli Defense Forces, the Mepro 21 is a maintenance-free, dual-illuminated, red dot reflex sight especially designed for quick and instinctive accurate shooting. This advanced optical sight is great while on the move in close quarters where the use of both eyes is critical. The fiber optic light collection system works during the day and transisitions seemlessly to the self-powered tritium at night. The Mepro 21 provides instant, all light aiming without batteries, and can work in tandem with a magnifying scope. Included is a Picatinny rail mount.