Product review (3 stars): Not really filtering much at all.
The plastic is thin and the wall mount and connections are not really even sturdy enough to hold up to hanging it with water in it.  It falls apart just handling it.  After looking it over and installing it, I decided to remove it.  The way my dryer sits on the shelf, it doesn't have the extra 8 to 10 inches behind it to put this round filter and there is limited room beside the shelf for it.

This item was missing in shipment for several days and I got a refund from Amazon.  Later a person down the street brought it to me as having been left with them by mistake.  I had already purchased another brand and flatter type that is actually a filter.  Amazon insisted I keep it rather than return it.  It'll probably just end up in my storage, unused.

I thought it was actually a filter.  It's not.  It just blows air from the hose out the holes in it's top.  There is a little water below that is supposed to catch the lint but due to the pressure it just blows out the holes and never reaches the water.  Not only not filtering but actually clogging up the output of the dryer by restricting it's output significantly.  Not to mention you can no longer directionally control where the output air goes as it exits all around this device.

Just not what I thought it was.  I thought the air was going to go through a filter and be pushed through the water to catch the lint.  The air makes limited surface contact with the  water. The vast majority of air and lint never gets filtered.  Most just goes through the hose and out the holes in the top.