Product review (1 stars): Misleading size.  Worthless.
This product is not the right size for an Emerson HDC-12.  The filters are 1/2 the thickness of previous filters I've used with my Essick Moist Air humidifier and the length is 1 inch shorter.  These filters are too small and flimsy to fit securely in their holders.  It's been unusually warm here this fall, so I'm just getting around to trying them.  It's just past the return date so I'm now stuck with this junk.