Meprolight FT Bullseye fiber-tritium optical rear sights are compatible with standard size Glock pistols, require no front sight, and are designed for compatibility with most holsters with no adjustments or modifications needed. The bullseye sight picture allows for intuitive and rapid target acquisition. They also feature a fiber optic/tritium combo for efficacy in both bright-light and low-light conditions, so you can shoot accurately in broad daylight and under the cover of darkness. No batteries or switches are needed, unlike WMLs, and the tritium in these night sights is guaranteed for 12 years.
