Meprolight Tru-Dot sights are up to 20% brighter than other tritium sights. The 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.
Smith and Wesson 3900, 4000, 5900, and 6900 Novak
Sights have their own Tritium gas light source - no batteries and no charging required
Sights are not affected by weather or gun solvents
On some models gunsmithing is required
These are the green tritium lamps
Sights offer 12 years of illumination