Product review (2 stars): Fits but does not work the same
I got these since I could not find a local store with the HDC-12 filters from Essick.  Well  They don't wick up the water that well and even with a humidifier additive to prevent mold and mildew, these were growing mold/mildew within a few weeks and I always clean out my humidifier when I change these.  I am off to find the real Essick brand ones which worked for me for years without a problem.