Basically it's a marine fume fan (bilge pump fume evacuator). I read the tech page and it claims that it produces 800CFM of air. It also claims that it draws 60amps @ 13.88V = 833 WATTS!!! That will put a noticeable strain on your alternator.
Just as a reference, I did some calculations on my 1.5liter D15Z1 VX motor and came out to roughly 175CFM at WOT (wide open throttle). Most Bilge fume pumps can put out 250CFM and cost <$40. That would put less strain on your alternator as well.
For the $300+ price tag....I would seek a different route.
It is only made to be used during WOT and most sites I've seen on it think it is a joke that it cannot possibly move enough air to increase HP.
If you were to somehow rig it to be on all the time you'd need to modify your electrical system to handle the extra current, and then you'd probably loose any FE gains, plus I don't think its motor can handle being on all the time.
I once saw some guys who installed one as part of their turbo experimentations and I think with the thing installed it dyno'd a few less horsepower because of the restriction caused by the fan (on an NA motor, not turboed). They just did it because they knew it was junk and wanted to show off their debunking skillz.
Basically he had a built-up JDM, 3-stage VTEC 1.5L in an Integra GS-R with a Nissan Skyline RB20 Turbo set to Zero PSI. 35mpg and all kinds of HP on tap.
So if I understand it correctly, if you reduce the pumping losses with a super-mild turbo at 1-bar, then you can gain some FE. This results in 14.5 PSI at the MAP sensor, which is essentially standard atmospheric pressure (29.92 inHG for US weather watchers). But, that doesn't mean the turbo pushes that much force, just enough to make up the difference.