Product review (4 stars): They work well, but not for as long as the originals
I am running 3 humidifiers with these filters.  They work well for about the first 2 or so months, but they do not last for a full season.  (The OEM filters are more expensive, but I think they last longer.)  And yes..., I do know that the instructions say to change them every month, but let's get real - how many of us really do that or can afford to change them every month.