The Trijicon® Tritium Suppressor Height Sights Glock® 17 / 19 / 22 / 34 Black Front & Rear are three-dot iron sights designed to improve your low-light shooting accuracy without needing batteries. Boating a shock-resistant design, the tritium gas lamps are contained within a protective aluminum cylinder with additional silicone rubber cushioning for superior protection and each lamp is capped with a sapphire jewel that evenly distributes the light from the lamp while also providing an extra layer of protection from punctures and cleaning solvents.