This is a single replacement cushion for use with the ResMed AirFit F10, AirFit F10 For Her, Quattro Air and Quattro Air For Her. Select size when placing an order. Compatibility: This cushion is compatible ONLY with the following ResMed full face masks:AirFit™ F10 Full Face Mask with Headgear AirFit™ F10 For Her Full Face Mask with Headgear Quattro™...