Product review (1 stars): I thought maybe if I wet it first it would work better but that made it so limp it wouldn't stand ...
I bought this filter instead of the Sears Kenmore filter mainly because there was free shipping on this one and not on the Kenmore.  That was a big mistake.  Do not buy this filter.  It is about half the thickness of the original filter although they both say "Approximately 1 inch".  I couldn't get it to stand up straight enough to get the top back on the humidifier.  I thought maybe if I wet it first it would work better but that made it so limp it wouldn't stand up at all.  I had to put it outside and let it dry out before trying again.  I finally got it in by using tape to hold the top together.  I'm sure when I take it apart to clean the humidifier that will be the end of this filter.  I wouldn't recommend this filter to anyone.