This Dual-Wall Spring Air Cushion is designed for use with all Mirage FX & Mirage FX For Her CPAP and BiLevel Masks. Designed with a gel cushion coated with soft-touch frosting to provide comfort and even pressure distribution. The unique gel cushion design coated with soft-touch frosting provides comfort with an even softer texture and reduced pressure distribution at the nasal bridge to avoid soreness, irritation and discomfort commonly felt in this sensitive area. At the front of the Mirage FX's Spring Air cushion is an in-moulded vent ring that disperses air gently and quietly away from the user and bed partners.