I'm selling this filter because I replaced my humidifier and no longer need it. This is a cleaning filter for steam humidifiers, with 16 circular filters that are easy to use. - Model: XQF-C020 - Contents: 16 cleaning filters - Application: For steam humidifiers - Shape: Circular with a hole in the center Although unopened, there is some dark debris on them... (see photo 3). It's not mold, but please refrain from purchasing if you are concerned. I have opened the package, but I will also include an additional 8 unused filters.