Product review (1 stars): Worthless
I bought these for my Hamilton 12HF humidifier.  They fit exactly.  However there is a coating on the filter that the box says should not be washed off as it's for "proper water distribution".  Well I had the filter in my humidifier for around 2 months now with it on and tonight I checked on it and the drain pipe was clogged with this white sandy residue.  I was like what was going on.  I opened the humidifer only to find the bottom where the water drains to was filled with the same stuff.  It's the special coating that they said should not be washed off.

I had to remove my drain pipe and flush it out.  I then had to clean up the mess inside my humidifier.  Remind you that it's only been running for 2 months.

This product is worthless.  I thought I was getting a deal when I bought them but now I know why they were so cheap.

I will go with a different brand tomorrow at a local store.