TRUGLO TFX PRO Tritium & Fiber-Optic Xtreme Handgun Sights, Ruger SR Set (TG13RS1PC) Fully protected TFO technology encapsulated in a virtually indestructible configuration Impervious to oils, chemicals, cleaning solvents and ultra-sonic cleaning processes Provides great visibility in all shooting conditions Utilizes quality Swiss tritium for maximum brightness Front sight FOCUS-LOCK for fast and accurate shooting