6pk of Ultra Fine Filters made by Philips Respironics. The filters are made of white fibers. The filters are designed to add additional filtration while using your CPAP or Bi-PAP machine. Most commonly used in homes with high pollen or dust particles as well as homes with pets. If neither one pertains to you, you can still benefit from the use of an Ultra Fine Filter as it will still add filtration of room air prior to you breathing it through the machine.
The filters are disposable and are not meant for cleaning! If you happen to get the filter wet, dispose of it and use a new filter. These filters are meant to be replaced every 1-2 months depending on the need for replacement. You will typically see the filter change from white to slightly grey or even black. It is extremely important to change this filter and should be considered as important as your Home Furnace filter! Lack of cleaning of the pollen filter and switching of an Ultra Fine Filter could cause your CPAP or Bi-PAP machine to overwork and eventually fail!