Product review (1 stars): Clay washes off, causing problems in the humidifier
Purchased this because the clay coating on the metal mesh (which is OEM-like) is supposed to provide more efficient use of the water by absorbing and allowing the evaporation of more water from the filter.  Within 2 weeks, all of the clay was loose and washing off of the filter, clogging the drain tube.  I highly recommend avoiding this particular brand and style of filter.  The metal-only filters from BestAir may be OK but the clay and metal ones are not.