When you need to make a fast and accurate shot, brightness counts. Truglo brought fiber-optics to the shooting sports industry years ago for this very reason. Truglo is now paired them with their tritium night sights to create a consistently bright sight picture - day or night! Their patented combination of Tritium and Fiber-optic technologies unites the best of both worlds. Whether you are in glaring daylight or complete darkness, you can count on TFO to provide a bright and reliable sight picture. Uses Truglo patented technology The ultimate handgun sight 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 standard holsters Snag-resistant design Fits Glock 17 / 17L, 19, 22, 23, 24, 26, 27, 33, 34, 35, 38, and 39.