Product review (5 stars): Can be modified to fit many cool mist humidifiers
I was not having any luck finding a replacement pad for my Honeywell cool mist humidifier, and came across this. It looked to be made of the same material as the original pad, but the size was way off. The size is about 11 long and 5.5 inches wide. The pad is designed as a loop, so if you cut it in half, you'll end up with two 11 by 5.5 rectangles per pad. There are a total of 2 pads per pack, so you'll get four 11 by 5.5 rectangles that can be then cut down to fit.

It was very easy to cut this down. It's thick, so a knife works best, but some heavy duty scissors would work as well.

It works just as good as the original pad. Best of all, it's very inexpensive - I can cut this down to make 8 pads that fit my humidifier, so I have enough replacements to keep me going for a few seasons of use at a MUCH lower cost than the "real" pads.

It is treated to help prevent mold.

If you need a square or rectangular pad for a cool mist humidifier this may be an option to look into.