Product review (5 stars): Not a replacement pad for Duracraft AC-809
I did a search on Amazon using the term "AC-809" and this filter popped up, so I bought it. It did NOT fit our Duracraft humidifier directly, but was fine after a bit of trimming with a tin snips (it has a metal foil backing). Good quality, works great, next time I'll pay more attention to the fine print.