When it comes to tritium gun sights, aluminum sleeves and painted-on white rings are the norm. Night Fision breaks the mold, literally. Their patented, injection molded sleeve design not only holds the tritium vials securely in place, it creates a brighter and more durable ring, they call The Perfect Dot(TM), that provides maximum visibility both day and night.Features:a Brightest Tritium Night Sights on the marketa Domed lens collimates tritium rays for a sharper sight picturea CNC Machined out of high quality steela Black Nitride coating used to improve wear and corrosion resistancea Installation: Gunsmith Recommendeda Built in the USA with Swiss Tritiuma Fits Glock Optics Ready 17, 19, 22, 23, 34, 35, 40, 41, 45