Three main things to check...is the knurling grippy to a point you could use it to file? Does the flashlight feel hard to a surface squeeze rather than kind of soft like most Chinese made lights? Did you buy from an authorized retailer?
Yeah that's why I bought it from this seller...
How can you guys normally tell if a surefire is fake or genuine? I suppose those Chinese guys making fakes these days do a pretty good job though..
I've never seen a Surefire that had really grippy knurling. it's one step above a maglite in knurling IMO
I like really grippy knurling
Just a few years back, SureFire models had cheese grater style knurling. Some of the more recent offerings are just too smooth.
I like cheese grater knurling. bring it back