Disposable Standard Filters for AirSense 10， AirCurve 10， and S9 Series CPAP Machines (12 pack)<div style="text-align: left;"><strong>[Product Information]</strong><ul><li class="showHiddenFeatureBullets"><span class="a-list-item"> 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. </span></li></ul></div><img src="http://ecx.images-amazon.com/images/I/11cz0LHRjNL.jpg" noproxy>