Glowing bright both day and night, 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. Illuminating elements are encased inside a?virtually indestructible chemical and shock resistant capsule and the CNC-machined steel is protected with a rust-proof Fortress finish. There is even a highly visible white ring surrounding the front fiber to make it even more visible, encouraging the eye to rapidly focus on the front sight for a fast and accurate sight picture.