OK, this is like the Goldilocks & the Three Bears of tritium keychains. The first set we featured was by far the coolest and most coveted, but also the hardest to acquire. Many readers deemed the task impossible. Then there was the second batch. That one was easy to acquire. Unfortunately, while the trademark glow of everyone's favorite radioactive isotope of hydrogen was still there, the overall effect was...I don't know. I have one of these tritium keychains and when it's not glowing, i.e., when I'm not surrounded by pitch blackness, it just looks like a cheap hunk of plastic.
But the tritium keychain presentation you see here, crystal clear tubular vials housed in titanium alloy protection shells, could be the Baby Bear of the trio. Just right. Like all tritium applications, this series naturally beams brighter and brighter the darker its surroundings get. Approved for use underwater, at depths up to 100 meters, many SCUBA fans use the gaseous isotope as a beacon or to illuminate their watches during dives. Tritium also has a very long half life, so the keychains' auto-luminescence should span around 25 years.
And like the first, but unlike the second set of keychains, these tritium creations look pretty cool. The titanium housing is sturdy and rugged, noticeable without overshadowing the main event. Goldilocks approved.
Titanium alloy protection shells measure 1.4" long and 0.4" in diameter. The tritium tubes themselves are 1" long and 0.1" in diameter.