Product review (1 stars): These filters are much shorter than the WF2 filters they ...
These filters are much shorter than the WF2 filters they are intended to replace.  As a result, air bypasses the filter in my humidifier, making humidification much less efficient.  With a proper-sized filter, the tank is half empty after an overnight use - with these filters, only an inch is vaporized.  I was able to cut one of the filters to fill in the gap in the air intake, making them suitable for use in my humidifier.  These should NOT be sold as WF2 filters.  The size is not correct to be so advertised.