Product review (3 stars): Emerson MoistAIR Humidfier Wick Filter
This filter works OK.  But as a caution, you do have to cut the filter to fit your humifier.  The OEM - MAF2 product is cut to fit but this one is too long.
Once you install the filter and use it, do not try to clean it -- it will fall apart.  Use it for 3-4 months and install a new one.