Truglo's Tritium night sights transition from standard 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. This sight set is compatible with Glock 17/17L/19/22/23/24/26/27/33/34/35/38/39.