Trijicon Di Night Sight Set For Smith & Wesson Shield ' Building on decades of proven engineering and manufacturing excellence in tritium and fiber optic aiming solutions comes the Trijicon DI Night Sights. Designed for shooters who want daylight brightness and a constant aiming point, the Dual Illuminated Trijicon DI Night Sights are equipped with an industry-first: a patent pending interchangeable fiber. This proprietary design not only allows the shooter the ability to replace the fiber in the field, it allows the user to choose among several fiber and ring retainer colors to configure a personalized aiming solution. Trijicon DI Night Sights feature a chemical and heat resistant fiber, finished with the same proprietary technique as the Trijicon ACOG, coupled with a tritium lamp capped with a sapphire jewel. This dual-illumination technology amplifies collected light, ensuring an ultra-bright aiming point in any light from daylight-bright to low-light to complete darkness. Trijicon DI Night Sights offer shooters the unique features needed for an any-light pistol aiming solution, with the durability and reliability Trijicon is known for. Features Dual Illuminated Brightness in Any Light User-Replaceable Fiber Optic Additional color choices for fiber and threaded retainers available for users to tailor their aiming point to suit their needs Tritium phosphor-filled glass lamp illuminates sights for high visibility in all lighting situations Fiber optic and tritium vial are held in place by a sturdy housing machined from solid steel for maximum durability Steeply hooked front surface of rear sight assists in emergency one-handed slide manipulations