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: Perfect Dot(TM) Night Sights with added daytime florescent or phosphorescent ring Brightest Tritium Night Sights on the market 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 Fits Glock Suppressor Height 17 17L 19 22 23 24 25 26 27 28 31 32 33 34 35 37 38 39 45 48