The new generation of Tritium Watches are the easiest in the world to read in low light conditions and even in total darkness. The light emitting devices require no battery power or any other form of charging; and never needs servicing or maintenance. Tritium gas is captured in tiny; airtight vials; sealed under high pressure; are resistant to water; oil and the most corrosive materials. A very safe and very minute quantity of tritium lights up the dye. This same technology is available in many firearms for use in gun sights. Most hunters and marksmen are already familiar with this great technology. If its important for you to tell the time quickly and easily in low light or total darkness; then a Tritium Watch is exactly what you need. Tritium watches glow up to 100 times more brightly than ordinary luminescent watches. And they require no external light source to recharge the illumination.