It literally does nothing but spin the tiny fan.
It doesn't filter anything at all first and foremost. I bought it because I liked that it was a "reusable/washable filter" but that seems to be because it also never gets dirty..  . Because it never collects any. After months of use (conveniently after I can't return it and it stopped working) it hasn't collected anything but some very minor surface dust that's less than you would get just falling on any open surface in your house. Stay FAR away from this one!
Rating: 1 stars