Buy air filters for CPAP cameras from the series: S9, AirSense 10 ELITE, AirSense 10 AUTOSET, AirSense 10 AUTOSET FOR HER AirCurve 10 and S10 from ResMed. Filters help protect the device from contaminants such as dust, pollen, dander, etc., and ultimately allow patients to breathe clean air. Filters should be replaced every six months, unless they are mechanically damaged or heavily soiled (it is harder to breathe, the pump works louder) then they should be replaced more often. Replacement of air filter 1. Open the air filter cover and remove the old air filter. The air filter is not suitable for washing and reuse. 2. Place the new air filter in the air filter cover and close it. Make sure the filter is tightly placed so that it prevents it from getting in at all times water and dust to the device.