Trijicon HD Night Sight Set Yellow Front, Glock 20 21 29 30 41 - GL104Y.PTraditional iron sights are often ineffective in low-light situations, so we did something about that. Trijicon iron sights for Glock handguns excel in a wide range of lighting conditions (including low light) and are built with our legendary durability to handle whatever comes their way. Take advantage of superior technology for aiming solutions you can trust. Choose from Trijicon Bright & Tough Night Sights, HD Night Sights and HD XR Night Sights.