Glowing bright both day and night, TFX sights are always ready. TFX takes the award-winning Tritium + Fiber-Optic technology even further with all the features their customers requested: compact 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-resistant FORTRESS FINISH . Product Features Fully protected TFO technology encapsulated in a virtually indestructible capsule Impervious to oils, chemicals, cleaning solvents, and ultra-sonic cleaning processes Unmatched visibility in all shooting conditions 24/7 Assembled in USA with quality Swiss tritium for maximum brightness Glows in the dark no batteries or light exposure required Front sight FOCUS LOCK for fast and accurate shooting Concealed fiber cannot be seen by target FORTRESS FINISH nitride protective coating Fits standard holsters Patented