Filters are the first line of air filtration defense for your CPAP system and should be replaced when dirty or every month. Standard filters trap large floating particles such as cat hair and dander. Your machine will typically come with a standard filter.
The Disposable Standard Filters for AirSense™ 10 and AirCurve™ 10 and S9 Series CPAP Machines (1 pack) is a single standard filter for the AirSense™ 10, AirCurve™ 10, and S9 series by ResMed. The following machines are compatible with the standard filter.