Standard fiber-optic sights use a thin rod of light-gathering fiber to produce a bright aiming point in daylight. They work well in good light conditions but provide no illumination at night or in dark environments. Standard tritium sights are the opposite — they glow reliably in low light through radioactive self-luminous inserts but can be difficult to see quickly in bright daylight. TFX (Tritium + Fiber-Optic) combines both elements in a single encapsulated unit. The fiber-optic provides the bright, high-visibility aiming point in daylight, and the tritium maintains visibility at night and in low light without batteries. TFX sights do not require any switching between modes — both technologies are active simultaneously at all times, and the dominant illumination source is automatically the one most useful for the current lighting condition.

TRUGLO’s TFX encapsulation places the tritium and fiber-optic elements inside a sealed, chemical and shock-resistant capsule rather than leaving them exposed or covered only by a soft plug. This protects against oils, cleaning solvents, Hoppes, CLP, and other common gun cleaning chemicals that can degrade the glass fiber rods in conventional fiber-optic sights over time. The capsule also survives ultrasonic cleaning processes, which are commonly used in professional gunsmithing and armorer work and are known to damage unprotected fiber-optic elements. The FORTRESS FINISH on the exterior steel provides corrosion resistance against sweat, moisture, and field conditions.

Tritium is a radioactive isotope of hydrogen with a half-life of approximately 12.3 years. Tritium sight inserts are at their brightest when new and gradually dim over time as the tritium decays. After approximately 12 years, the inserts will be at roughly half their original brightness — still visible in low light, but noticeably dimmer than when new. Most manufacturers, including TRUGLO, provide replacement or warranty programs for tritium inserts after a defined service period. No maintenance is required during normal service life, and the fiber-optic element continues to perform at full brightness regardless of tritium age.

Glock sights are pressed into a dovetail cut in the slide and require a sight tool or punch set to remove the factory sights and install new ones. This can be done at home with the appropriate Glock sight pusher tool. However, because this involves a press fit into a steel dovetail, improper installation technique can damage the sight body, the dovetail, or the slide finish. If you are not experienced with sight installation, a gunsmith can install the sights in a few minutes at low cost. TRUGLO includes installation instructions with the sight set; consult those instructions or a qualified armorer if in doubt.

TRUGLO specifies that the TFX sights fit standard holsters. The snag-free profile is designed to avoid hanging up on the holster body during the draw. However, taller sights can conflict with some retention holsters that have a sight channel designed for standard-height sights. If you use a holster with a narrow sight channel, verify with the holster manufacturer that it accommodates suppressor height sights before installing. Many duty and competition holsters are already designed for suppressor height compatibility, but some concealment holsters with minimal clearance may require verification.