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 MOS 17 19 22 2334 35 40 41 45