CPAP Filters for AirSense 11 by ResMed The AirSense 11 Disposable Standard Filter is designed to improve air quality and protect your AirSense 11 CPAP or APAP machine from large airborne particles. The filter is not washable and should be replaced every 2-6 months depending on dust accumulation and household air quality. CPAP users with allergies may want to consider the polyester-free AirSense 11 Disposable Hypoallergenic Filter which effectively filters out both fine and large airborne particles. Key Features: Compatible with ResMed AirSense 11 AutoSet or Elite models. Captures Large Airborne Particles (dust, pollen, pet dander) Available in packs of 2 or 12 or 50. Prolongs Machine Lifespan with regular use and replacement