The TFX Pro Night Sights are constructed with duty or military use in mind. These sights feature both a Tritium vial for constant illumination, as well as fiber optic rods that amplify ambient light. Not only do these sights have both Tritum vials and fiber optics, but they are hermetically sealed in a redesigned TFX capsule, that provides superior protection against oils, chemicals and cleaning solvents. No more worrying about damaging your sights when cleaning! Front Sight features an orange outline, providing a contrast in colors and faster target acquisition. Rear sights features a U-notch design and angled front face for emergency slide racking. Si Mfg: Truglo