APX Night Sights Kit featuring tritium gas-filled lamps with a sapphire front lens which focuses light and is impervious to solvents. The sapphire lens-enhanced tritium vial is one of the brightest in the industry. The gas-filled lamps are silicone cushioned to take years of use and come with a full warranty. Matte finish. The lamps glow bright green in the dark and have white outlines that show as white spots in daylight. Note: if marked H3 on the metal sight, the product contains tritium gas and is a night sight, regulated by the US Nuclear Regulatory Commission. Sight kit must be fit by a professional gunsmith. Not compatible with the A1 or any carry model.