This clone of the SureFire U2 Digital Ultra looks pretty convincing on the outside, but you'll soon find that the selector ring at the base of the bezel does not do anything - in fact, it does not even move. The unit has a tailcap switch that allows two intensity levels. And it is not hard anodized; it appears to have a Type II anodize finish, as it failed "The Knife Test"... Also, the rather beefy pocket clip found on the real thing is absent from this clone. But the unit does have a real glass window (or "lens"), and is water-resistant - though there is some leakage around the tailcap switch. As far as I'm able to determine, the light comes from a Luxeon III LED near the bottom of an almost mirror-smooth reflector, and the unit is powered by 2xCR123A lithium cells.