Meprolight Tru-Dot, Sight, Fits Glock 17, 19, 20, 21, 23, Green/Green 0202243101 MEPROLIGHT combat proven self-illuminated night sights enable you to hit stationary or moving targets under low-light conditions with dramatically increased hit probability. Designed as replacement parts for the standard weapon sights" MEPROLIGHT'S Self-Illuminated night sights can be mounted directly with minor modifications. Superior production methods and rigid quality control have made MEPROLIGHT the first choice among law enforcement agencies" defense decision makers and major weapon manufacturers.