Product review (2 stars): Much thinner and more flimsy than traditional filters
These filters are much thinner than normal filters (about half the thickness).  The result is that once they get wet (after a day or so), the top 1/3 of the filter opens up like a flower within the humidifier and are much less effective.  I've been binding them together with twine in order to use up my pack of 4, but will not purchase again.