Product review (4 stars): Better than Protec
These are the most like the original filter that came with the Humidifier.  I did purchase and use the Protec filter, which I was very displeased with.  The so-called reinforcement in the Protec filter started falling apart soon after use.  These filters were much better.  Only thing is I wish there was something in them to keep them from turning brown after drying out from the humidifier not being turned on.