Night Fision's patented, injection molded sleeve design holds the tritium vials securely in place using ballistic materials. Night Fision night sights carry more tritium than the average night sight on the market and a domed lens engineered to create a crisp, defined glow. Features: Brightest Tritium Night Sights on the market Domed lens collimates tritium rays for a sharper sight picture CNC Machined out of high quality steel Black Nitride coating used to improve wear and corrosion resistance Installation: Gunsmith Recommended Built in the USA with Swiss Tritium