Simply put TRUGLO manufactures bright ideas. When TFX PRO sights immediately took off and gained critical acclaim Truglo noticed that the world of TRITIUM night sights needed a similar upgrade. Starting with the brightness and durability of our original TRITIUM night sights they added all of their PRO level features to give you the advantage when you need it the most. Front sight FOCUS-LOCK ring for even faster focus Quick and accurate U-notch Design Angled rear sight edge for emergency one-hand operation Assembled in USA with quality Swiss Tritium for maximum brightness Unmatched visibility in low-light shooting conditions or complete darkness Utilizes quality Swiss tritium for maximum brightness Glows-in-the-dark - no batteries or light exposure required FORTRESS FINISH provides a permanent protective coating for maximum protection Snag resistant design / fits standard holsters Glock 42/43/43x/48