Product review (5 stars): $6.49 each and work better than OEM product.
I bought the 6 pack about 2 1/2 weeks ago and placed one in my Aircare humidifier. This is better than the oem product that came with my humidifier.  At this price you are paying about $6.49 per filter--compare that to other prices around the $20 range for 1 filter.

These have the metal mesh surround which keep it from eventually losing shape and falling into the water.  Mine did turn slightly brown on top pretty quickly, but no issue at all. It still works just fine. I added a minute amount of bleach once when I noticed an odor recently and problem is gone. There is an slight odor to the new filter which quickly subsides. Heck with points on my American Express card, I paid actually less per filter. I searched hi and lo fir something to work in this humidifier. This is it, and it can be cut to fit my smaller Aircare also.