Enhance your shooting experience using the Trijicon HD XR Night Sights for Glock Standard Frames (MOS). This two-piece kit consists of a narrow front sight and a rear U-notch, featuring battery-free green tritium phosphor lamps that glow in the dark. While the front sight has one tritium lamp encircled by a photoluminescent orange disk, the rear U-notch only bears two tritium lamps, one on each wing. The set's design is aimed at increasing visibility, speeding up target acquisition (even in transitional lighting), and improving distance shooting. For added durability, the sight's lamps are encapsulated in aluminum cylinders and have silicone cushions. For protection against gun-cleaning agents and proper distribution of light, the lamps are also sealed with sapphire windows.