Surefire is the US name for ITS industries series of lights. There are several places with some good prices: http://www.botac.com
(Disclaimer: I've read several posts about customer service issues...no first hand experience. But they generally have the lowest prices)
Doh!! Madecov is right -- I meant to say "Streamlight" in my post. They make the M3 and M6 brands of light that are popular.
The X200A is by Surefire. Same deal on sources and prices...Botach tends to be the best but their customer service rep is spotty. (As a matter of fact, I placed an order with them a week ago and it hasn't shipped yet. Hmmm.....)