Looking at their data sheet, I am highly suspicious of their claims being true, especially the antenna gain spec (my guess is they are including their pre-amp gain to make it look more appealing). Also, the wide frequency range means it will suck across most of them.
It's a 30? directional antenna, so it'll be okay for trying to find the direction a signal is coming from, but it will take some effort.
Edit: stoopid a$$ punctuation bug...
30 degree...
ETA:
when I'm not on my phone, I'll link you a couple alternatives that will cost the ISM bands, and be noticeably cheaper. (Although you still have to have a spectrum analyzer).