Looks very similar to this one - http://www.dealextreme.com/p/x2000-flood-to-throw-zooming-glass-lens-cree-p4-led-flashlight-3-aaa-13732 - but if its rated at 5W, then the emitter has to be a lot better than a P4. I assume the 3xAA is a typo.
I've seen them on Ebay a couple of time with bike brackets for cycle lights, this one http://www.ebay.co.uk/itm/CREE-Q5-240-lumen-LED-BICYCLE-BIKE-HEADLIGHT-MOUNT-/130602802679?pt=UK_SportsLeisure_Cycling_Bike_Lights&hash=item1e68889df7 seems exactly the same (5W?) but cheaper.
5W for a tenner - tempting!
I looked at these earlier today, the lumens rating was 480 - 500. That's massively bright isn't it?