ResMed AirFit F20 Full Face Mask with Headgear, The AirFit F20 delivers a one size fits all mask solution. Regardless of face shape or size, the AirFit F20 provides a comfortable fit with a secure seal. Simply choose from three interchangeable cushion sizes to contour perfectly to your face. Patients also have a clear line of vision for watching TV or reading. The InfinitySeal silicone cushion design maintains a consistent seal even under the highest therapy pressures.