Seriously, stay away. Got that light, and it uses a horrible control ring thingy (i.e. no magnet, but a physical lever, rotating a mechanical knop inside on the PCB). The O-ring was totally stuck, prevented rotation except with EXTREME force. Trying to repair it broke it completely.
Did send it back to china for them to repair it (which was for free - great that part, except the shipping cost)... only to come back a month later with a pretty badly fixed head, making the reflector assembly wobble around.
Gave up on the light, its just not woth sending back and forth, because the whole thing is a construction mistake. Its also nearly impossible to mod it into a reasonable driver/controller sheme, due to the fact it was build around the lever thingy.
When I got it to run it WAS pretty bright (for the 45 minutes or so it worked in total), but its not worth the price in a world where you can get a Nitecore TM-11 or something similar for less money.