With regular use the mask cushion loses its ability to seal. This coupled with hygienic concerns makes replacing the cushion important when needed. This will replace the cushion on the Quattro Air or AirFit F10 full face masks.
Recommended replacement as needed for proper seal. Wipe down once a day with a damp cloth and wash in warm, soapy water once a week with a gentle soap.
This item is just adequate. I've yet to find a full face mask that is very good. The price of this small replaceable part is far excessive.