LumiNova Sights provide high targeting performance in all light conditions. Dots made from a photo luminescent material. Dots require a "charge" from a light source (sunlight, flashlight). Charged dots highly visible in low light environments. A quick 30-second "charge" of the dots by your tactical flashlight will provide 20-30 minutes of intense glow. Recharge to maintain maximum brightness. 5x brighter than tritium during initial glow.