Product review (5 stars): It does exactly what it's supposed to do.
I have two Essick humidifiers in my house, and though one is a fairly old model, and the other is brand new, they both continue to use the same exact filter, which is really great because I don't have to deal with two different kinds of filters.

These filters are meant to last one winter season, and then when Spring comes, they get tossed into the garbage.  I have been using this brand, the 1041, filter now for about 10 years.  It's always stayed the same quality, and has never failed in all this time.  So, I am very happy with the filter, and can recommend it as a "buy" for those who have need for this model.