Thanks for all the observations...Some additional comments:

I've worked with LED's since their introduction way back when, but this
little keychain model is my first UV led. It is indeed a true UV,
probably 395nm or so. I didn't get much use out of it, the mom switch
allowed for quick on-off use on some fluorescent items I had laying
around. I don't think it lasted more than 60 seconds in total time. It
was quite bright in the UV with a bit more visible light than a
traditional "black light" tube UV-B source. I wanted it as a small
convenient UV source for quick document checks but just as a little toy
really. (something I can admit to this group)

The seller said he will send a replacement. If he does, I'll check and
see what current typical UV leds run at and figure what resistance I
need with 2 2016 lithiums, maybe I can run it on a single 2016 for a
lower, more reasonable voltage, and leave some space for a resistor.

I questioned the reliability for a few reasons, mostly web chatter, but
in fact Inova, a reliable company, dropped their UV offering. I wonder
if reliability issues lead to that decision, or simply lack of market
interest.

Dennis Harper