When it comes to tritium gun sights, aluminum sleeves and painted-on white rings are the norm. Night Fision breaks the mold, literally. Their patent-pending injection molded sleeve design not only holds their tritium vials securely in place, it creates a brighter and more durable ring, they call The Perfect Dotâ„¢, that provides maximum visibility both day and night. Features: Perfect Dotâ„¢ Night Sights with added daytime florescence, Brightest Tritium Night Sights on the market, CNC Machined out of high quality 4140 steel, Black Nitride coating used to improve wear and corrosion resistance, Installation: Contact Professional Gunsmith. Built in the USA with Swiss Tritium.