TRUGLO TFX Tritium and Fiber-Optic Xtreme Handgun Sights for Steyr Mannlicher Pistols Unmatched Visibility in all shooting conditions, night or day; Glows in the Darkno batteries or light exposure required Front sight Focus-Lock Ring for even faster focus TFX Sealed Capsule Design provides maximum protection and durability; Fortress Finish provides a permanent protective coating; Impervious to oils, chemicals, cleaning solvents, and ultra-sonic cleaning processes Concealed Fiber cannot be seen by target; Snag Resistant Design fits standard holsters Machined and Assembled in the USA with quality Swiss Tritium for maximum brightness; Patented