Product review (3 stars): It's okay
I had bought a used humidifier from a friend who was moving.  She gave me some filters to go with it, but unfortunately I threw the boxes out as I used them.  Then I found this filter.  It seemed to fit but fell apart in about 2 weeks.  Came apart at the seam and just kind of disintegrated.  I ended up buying the size B, which is a little bit smaller but much more sturdy like they should be.