I don't think we have a Custom section here anymore, unless I'm mistaken, so I thought this would be the place to post this. It's either brass or copper. Little bit of a patina, but they both get their own and I usually can't tell one from the other. I haven't done the spoon test on it yet. It's Surefire E-series compatible, 2AA/14500. Double o-ring on head end. Tail has spot for one, but it's missing. I think I've had this at least 15 years. I'm thinking Balrog? Maybe TNC Customs?