FIME Group — Truglo Tritium Rex Zero 1 Pistol Night Sights use the brightest tritium available. CNC machined steel construction. Green front and rear. Fits standard holsters. Snag-resistant design. 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 the dark. Tritium does not need batteries and does not need to be charged with light – it simply glows!