Product review (1 stars): Poorly made, doesn't work well for long.
I've had several of these, and determined they just don't work as well as other filters in our humidifier.  With a fairly new Holmes filter, the humidifier was going through very little water.  Mineral deposits (using moderately hard water) had quickly formed a hard crust around the middle of the filer, so the upper half was always dry - it just wasn't drawing up the water past the deposit ring.  I tried to clean the filter and it fell apart - breaking at the seam and the black plastic that's supposed to reinforce it flaked off all over.  I found flakes of the plastic in the humidifier, too.  I switched to the BestAir H75 filter, and the humidifier is going through water rapidly again.  It's aluminum reinforced, performing better than the Holmes did when first installed.  I was prepared to pay more for a better filter, but the BestAir one turned out to be slightly cheaper.