The better you can see your sights, the better you can shoot. TruGlo brought fiber-optics to the shooting sports industry decades ago for this very reason. TFO pairs their fiber-optic sights with their tritium night sights to create a consistently bright sight picture day or night! TruGlo's patented combination of tritium and fiber-optic technologies unites the best of both worlds providing the same bright sight picture whether you are in glaring daylight or complete darkness. Fits: Model 20, 21, 25, 29, 30, 31, 32, 37, 40, 41 Nitride Fortress Finish Duty Proven CNC-Machined 24/7 Brightness Assembled in the USA DISCLAIMER: GLOCK is a federally registered trademark of GLOCK, Inc. and is one of many trademarks owned by GLOCK, Inc. or GLOCK Ges.mbH. Neither Sportsmans Outdoor Superstore nor this site are affiliated in any manner with, or otherwise endorsed by, GLOCK, Inc. or GLOCK Ges.mbH. The use of GLOCK on this page is merely to advertise the sale of GLOCK pistols, parts, or components. For genuine GLOCK, Inc. and GLOCK Ges.mbH products and parts visit www.glock.com.