It has blades. They are buried in the round base of the fan.
The airflow from those blades is ducted up around the inside surface of the airfoil shaped ring, and it draws in air and accelerates it out through the gap around the inside of the ring, which picks up the rest of the air it moves.
Seen similar used to ventilate fuel cells on aircraft, for maintenance work. Moves lots of air, but uses an outside air source to make it work.
No free lunch.
Cheers
Trev
I do understand how it works

thought it was just a neet way to make behind the radiator
That fan will have virtually no ability to generate a static pressure gradient. While it probably moves bulk air (how well I don't know), it won't be able to pull air across something with resistance (like a radiator). Based on the fact that it's a dyson I would have to guess it's probably not very good at what it's supposed to do, either. Another peice of gimmick dyson crap.
Hey Mark,
that's almost as good as a bog paper airplane