If you're looking for an alternative to traditional iron sights, Trijicon's Bright & Tough Night Sights may be for you. They are a self-luminous three dot night sight. The first choice of many major handgun manufacturers, Bright & Tough are standard issue with local, state, and federal law enforcement agencies. Each sight is designed to a specific handgun make and model. Trijicon Bright & Tough Night Sight features: Tritium Phosphor LampTritium-filled gas lamp provides superior illumination in no light or low light conditions. Sapphire WindowEach Trijicon lamp is capped with a sapphire jewel which helps evenly redistribute the light from the tritium lamp as well as protect it from solvents and puncture. Silicone Rubber CushionGives additional shock protection to tritium filled glass lamps within the aluminum housing. Protective Aluminum CylindersContains and protects the tritium gas filled lamps from heavy recoil and harsh cleaning solvents. White RingsAll Bright & Tough Night Sights feature a white ring around the glowing dots for daylight visibility. Trijicon® Suppressor/Optic Height Sights - Glock Standard Frames 600660