It contains a small glass tube containing a small amount of gas - tritium (hydrogen radioisotope), the resulting fluorescence can be within 30 feet within about 10 meters to draw your attention. Do not need the battery, which contains the material gas can be light for 10 years! Compared with other similar fluorescent key ring, the biggest advantage: can be used underwater 100 meters, can be used in harsh environments.

Tritium Related knowledge: pronunciation: chuān

  Because tritium beta decay will only release high-speed mobile electrons, will not penetrate the human body, no harm to the human body. And through the breath into the human lung tritium gas will not enter the metabolic system. Half-life of 12.5 years. Tritium gas luminescence technology has been applied in a number of civilian areas.