This is a copy of the Viair. I had one of these for a while and it worked very well for the price. I originally bought it as a spare, but sold it to a friend only because it took up as much space as my primary compressor (I got a smaller one for the spare).
The only thing I would caution, and that goes for many things from HF, is to carry a spare if you're going out alone and will be in a situation where having it is critical. If neither of those apply - it's a great deal.