Pro night sight glows in the dark with maximum brightness in low light or complete darkness as well as the day time with the angled quick accurate U-notch design rear sight and white front focus lock ring sight to make it even more visible and encouraging the eye to rapidly focus for a fast and accurate sight picture. TFX sights are always ready. Tritium Fiber-Optic technology is snag-free design, longer sight radius, and amazingly durable construction built to handle just about anything. CNC-machined steel is protected with a rust-proof Fortress finish.