Product review (1 stars): Fortunately, I easily solved the problem by trimming the ...
I had a problem with this order.  The replacement moisture filter did not fit my Duracraft DH 831 humidifier.  The instruction sheet that came with the humidifier calls for part No. AC 818.  The package the filters came in was labeled HC 819 & HC 818. The filter is about an inch too long.  The message I just received and to which i am responding indicates that HC818 and AC 818 are the same.  Apparently that is not true.

Fortunately, I easily solved the problem by trimming the filter to the correct size.  I need nothing further from amazon.

Phil Adams