Product Code: T56781III
These are the original Swiss made Trigalight Tritium capsules as used in many high-end Swiss made watches.
The electric energy in the trigalight is generated by the tritium gas, a low radiation beta emitter. When decaying the tritium looses electrons. When such an electron hits the powder layer it is captured and transformed into light.
Tritium vials are self-powered and do not require power, light or other sources to provide illumination!