BLACKWATER KR36 Titanium Alloy Tritium Vials Light Self-luminous 25Years for VIP2 and above is for $36.95 (instead of $49.95) and using BG points it’s possible to lower the price further to:
VIP2 |
VIP3 |
VIP4 |
VIP5 |
$31.04 |
$30.67 |
$30.30 |
$29.56 |
This keyfob doesn’t need light exposition to glow at night - it uses gaseous tritium (isotope of hydrogen) in a process called radioluminescence and lasts ~25 years (due to radioactive decay of tritium it looses half intensity in about 12 years - it doesn’t stop emitting light abruptly like discharged flashlight - instead it gradually glows dimmer and dimmer).
Here’s article about how this works: wikipedia: Tritium illumination.