Trijicon Fiber Optic front sights are designed with years of manufacturing experience and leadership using the industry's leading technology and processes. Trijicon Fiber optic sights feature a fiber optic front sight which can be replaced with fiber optics packs (Sold Separately). The fiber optic front post will absorb day light in order to provide a bright aiming point. At night it will absorb as much ambient light as is available in order to provide you with an aiming point. However fiber optic sights will not glow since it does NOT contain a secondary illumination source like tritium.Specifications:Trijicon Fiber Optic Sight Set GL701-C-601023Red Fiber Optic Front SightBlacked Out Rear SightHigh Visible Front SightDurability for Everyday Pistol UseClear, Precise Sight PictureOne Handed ManipulationComfortable to ConcealReplaceable Fiber Packs Available (Sold Separately)Limited Lifetime Manufacturer Warranty Steel HousingMatte Black FinishNote: Professional installation of these sights is recommended.Fits:Glock 17, 17L, 19, 26, and 34 9mm Luger pistol modelsGlock 22, 23, 24, 27, and 35 .40 Smith & Wesson modelsGlock 31, 32, and 33 .357 SIG pistol modelsGlock 37, 38, and 39 .45 GAP pistol models