3D Printed, Radioactive Tritium Flashlight — Runs for 20 Years Without a Battery
http://3dprint.com/39634/3d-print-radioactive-flashlight/
Sounds like a watch I had many-many years ago! (Couldn't wear it on site unless I was using it to test friskers - even back in the day of 30 mg windows for personnel friskers!) It was so bright I had to place it face down to let my wife go to sleep. 8) O:) [SadPanda]
I wore my Dads old Service watch from the 40"s to work at CNSI back in the 70's....... the HP's did not see the humor in the situation. If I remember correctly it had a 3 mr/hr reading from the dial. >:(