The Solar Powered Red Dot Reflex Optic has a dual power source. The Red Dot reflex optic can be powered by the sun via the top mounted solar cell or the included AA battery. Features solar cells mounted on top of the reflex sight will power the red dot whenever there is sufficient sun light on the solar cells; powered by the AA battery; electronic control panel has a red LED indicator when the Red Dot is powered by the AA battery; electronic control panel to turn on the Red Dot under AA battery power; adjust the brightness level up or down when powered by the battery; centerline is at 1.5 AR15 height; locking quick release Picatinny mount and unlimited eye relief. The LED is 100% safe for the eyes and the 2 MOA Red Dot has 5 levels of brightness.