[Trurolexer]

Originally Posted by VazLube

What I understand, T = Tritium and L = Luminova.

Tritium is radioactive which emits, and it glows, but it doesn't glow forever.
Luminova is activated by external light sources.

Nowdays watches are painted with Luminova lume.

Usually you see "T SWISS MADE T" or "L SWISS MADE L" to denote what lume is used.

Wiki info here

Nothing beats Timex glow dail! (requires battries of course!)

X2!!!