When you need to make a fast and accurate shot, brightness counts. That is why TruGlo designed fiber-optics to the shooting sports industry years ago for this very reason. TruGlo has now paired them with their tritium night sights to create a consistently bright sight picture, day or night! TruGlo's patented combination of Tritium and Fiber-optic (TFO) technologies unites the best of both worlds. Whether you are in glaring daylight or complete darkness, you can count on your TruGlo TFO sights to provide a bright and reliable sight picture. The TFO Low Set fits the Glock 17 / 17L, 19, 22, 23, 24, 26, 27, 33, 34, 35, 38, 39 and 45. Features: Unbelievable transition through all light conditions Glows in the dark No batteries required CNC machined steel construction Concealed fiber cannot be seen by target Fits standards holsters Snag-resistant design