XS Sights R3D Night Sights, Green Front Dot, Fits Glock 20,21,29,30,30S,37,41, Steel/Blued GL-R013P-6G XS R3D Night Sights feature a traditional 3-dot tritium" notch and post sight picture. The blacked-out rear increases contrast against the front sight. The front sight is available in orange or green and is equipped with Ember(R) Glow Dot Technology. Ember absorbs ambient light and glows in low light. The front tritium lamp charges the Ember dot making the front sight glow brighter than the rear at all times" keeping focus downrange. R3D sights are the brightest notch and post option for fast and accurate shooting in bright and low light.