Ok, thought I'd ask our brain trust since I'd no luck searching.
At a gun show I was at, a gentleman dropped a tiny white LED light down into a .22 barrel so I could see the bore and barrel. It was a small thing, about the size of a .22 round, but obviously smaller in diameter since it could be dropped in and slide back out.
Any idea what this was? I didn't think to ask the guy at the time about it.
Thanks!