Tritium night sights transition from standard white dot sights during the daylight to glowing green dots in the dark. Tritium does not need batteries. This set includes a front sight with a length of 1.0 inches and a rear sight with a length of 1.0 inches, both designed for easy installation on Glock 9mm Luger and .40 S&W models.Key FeaturesFixed Tritium Color: The sights feature a fixed tritium color for enhanced visibility in low-light conditions.Style: Designed with a square front and U-notch rear for improved aiming.Compatibility: Specifically compatible with Glock 9mm Luger and .40 S&W models.