TRUGLO Brite-Site Tritium Sight, Fits Glock 17,17L,19,22,23,24,26,27,33,34,35,38,39, Green TG-TG231G1 When the lights go out" your sidearm doesn't need to be left in the dark. Tritium night sights transition from standard white dot sights during the daylight" to glowing green dots in the dark. Tritium does not need batteries and does not need to be charged with light - it simply glows!