CPAP users, keeping your machine clean is key for good therapy and health. This 24-pack of Nispira ultra-fine air filters is a cost-effective way to stay on top of regular filter changes. They're compatible with popular ResMed models: AirSense 10, AirCurve, and the S9 series (including the S9 and AirStart). These are the fine, white filters that go in the air inlet to trap tiny particles like dust, pollen, and pet dander before the air even reaches your machine's main filter and you. Using a fresh filter helps ensure you're breathing cleaner air, which can make therapy more comfortable and help your CPAP machine last longer. Replacing these filters regularly (usually every 2-4 weeks, or as recommended) is simple and quick. Having a 24-pack means you're set for months, so you don't have to worry about running out. They're a generic/replacement brand, not OEM ResMed, but they're made to the same specifications and do the job perfectly. An essential maintenance item for anyone on CPAP therapy.