TRUGLO patented TFX PRO (Tritium + Fiber-Optic Xtreme) sights provide a 3-dot aiming system that is bright in daylight as well as low light and complete darkness - no batteries or light exposure required. TFX technology uses a sealed capsule design, press-fit retention rings, and Fortress Finish™ permanent protective coating that make the sights incredibly durable and resistant to chemicals and solvents that can damage unprotected sights. Front sight FOCUSoLOCK supports fast and accurate shooting and the concealed fiber cannot be seen by target. PRO version includes a U-notch rear sight for increased speed and accuracy, a bright orange FOCUSoLOCK ring on the front sight, and a forward-angled rear sight profile to assist in emergency one-hand slide operation. Fits the Ruger American Pistol®. Assembled in USA with quality Swiss Tritium for maximum brightness.