Glowing bright both day and night, TFX sights are always ready. TFX takes the TRUGLO 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-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. TFX sights will amaze even the most discriminant shooters. For Glock models 42 and 43 Product Features The first and ONLY of its kind Fully protected TFO technology encapsulated in a virtually indestructible configuration Impervious to oils, chemicals, cleaning solvents and ultra-sonic cleaning processes Unmatched visibility in all shooting conditions 24 / 7 Utilizes quality Swiss tritium for maximum brightness Glows in the dark No batteries required Concealed fiber can not be seen by target FORTRESS FINISH provides a permanent protective coating for maximum protection Snag resistant design Fits standard holsters Patented