Whatever you do, do NOT buy one of these. I'v had mine for about 2 years, and it was working great, then one night, nothing. The wire where it goes into the battery pack is either kinked or something, but there are no visible signs of abuse. My prognosis: SHIT Q.C.
On the other hand, I've had my Petzl Arctic for 10 years, and it's even got chew marks from my dog on all functional parts, and it still works like a champ. For my money, I'd definitely stick with Petzl.