Meprolight Tru-Dot sights are up to 20% brighter than other tritium sights. The green tritium front dot is slightly brighter than the rear sight to help the shooter focus on the target. Light tubes are sealed with a patented bonding process that makes them impervious to solvents and oils. Tru-Dot sights have a 10-year illumination warranty. DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.