What little info I can find about these things is they were made in the '40s-'50s and none of the others of this style I found online work. I have completely disassembled this one, cleaned all the corrosion from inside, cleaned all the contacts and it's now working perfectly. It's not blindingly bright since it is 1940's technology after all, but is very well made. I'd never drop it on purpose but it's heavier than it looks and obviously built to survive occasional accidental drops.