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; Built in the USA with Swiss Tritium; Extreme Low Co-Witness Blade; Fits Glock 17, 17L, 19, 22, 23, 24, 25, 26, 27, 28, 31, 32, 33, 34, 35, 37, 38, 39 (Including MOS Models)