Roscoe Medical S9 Hypo-allergenic Foam Filter. Disposable Hypoallergenic Filters for use with S9 Series, AirSense 10, Air Curve 10 CPAP Machines. Roscoe Medical S9 line of CPAP machines do not use reusable foam and disposable fine filters like other machines. These HypoAllergenic Disposable Filters are made of non-woven acrylic and polypropylene fibers with a polypropylene carrier. The combination of materials helps block even the very finest of particles.