Product review (1 stars): DOESN'T ABSORB WATER!  DO NOT BUY THIS GARBAGE.
This is a miserable filter because IT STAYS DRY even when its bottom is submerged!  This means that air is circulating around dry paper.  How much moisture is picked up from dry paper?  NONE!  I used to go through at least two water tanks every 24 hours with the pleated paper filters; it takes 3+ days with these pitiful expanded paper types (BestAir ES-12).  I waited three days too long to return them and am now stuck with this garbage that I'll have to throw away because I sure can't use them.  I wouldn't even dupe somebody on the auction site with these at a good price.  Maybe the manufacturer will have mercy on me, but figure the odds.

I found the pleated, absorbant paper kind from a different online vendor for a lot less cost.  Steer clear of these if you want your humidifier to humidify.