You're right about them not allowed in the U.S. The NRC considers the keyring to be a "frivolous purpose". But then, I'm one of those guys that hates the nanny state we're becoming. I bought it from a guy in Singapore. Gotta love the internet - an enemy to tyrants worldwide!

As for the safety of the vials, read this www.candlepowerforums.com/vb/showthread.php?t=107823
Just scroll down to the links from John N.

I just machined and drilled the polycarb around the glass vial. It's still a pretty substantial housing. Reduced it from a big honking piece of plastic to a smaller honking piece of plastic.