XS Express Sights are made for fast sight acquisition in all light conditions. Sights feature a low profile, snag free design and are easily installed. Includes a Tritium green dot front and a white vertical line rear sight. Tritium inserts are surrounded by a thin white line for enhanced use in daylight, Big Dot versions have a larger white outline on the front sight surrounding the tritium insert. The rear sight does not contain a tritium insert. Features: - Tritium Front Sight - White Line Rear (no tritium insert.