TruGlo's Tritium night sights transition from white dot sights during the daylight, to glowing green dots in the dark - no batteries or light exposure required. Assembled in the USA with quality Swiss Tritium for maximum brightness, these sights utilize CNC-machined steel construction with a snag-resistant design fitting standard holsters, and TruGlo's Fortress Finish permanent protective coating for maximum protection. Tritium Pro Night Sights retain the brightness and durability of TruGlo's original green Tritium night sights with added Pro features: a quick and accurate U-notch design, an angled rear sight edge for emergency one-hand operation, and white Focus Lock ring on the front sight for even faster focus.