TRUGLO Tritium Pro Brite Site Day / Night Sight Set Fits Glock M.O.S. 17/19/34/35/45, Front Sight Color Green W/ Orange Focus Lock Ring, Rear Sight Green, Glows In The Dark No Batteries Or Light Exposure Required TG-TG231G1MC

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 because it glows.