Product review (5 stars): Right Size, No Leaks
I had tried to use the knock off water panel, but it made my humidifier leak.  After some investigation, the problem was that the thickness of the cheaper panels varied.  If they were too thin, even by 1/4 inch, the water would not run down them properly and it wouldn't be caught properly in the frame to be drained out.  Instead it would drip on to the lower part of the humidifier shell and drip out.  Have not had that problem with these.