ResMed Swift FX Mask SystemLess mask. More you. With super soft fit and a minimal appearance, the Swift FX makes it easy to forget about your mask and remember what it's like to get a great night's sleep. Minimal design reinforces sense of freedom. Unprecedented softness, simplicity and stability. Flexible, fluid form follows facial contours and user movements. Promotes early therapy acceptance. Intuitive, virtually instant fitting. Stable performance, even at high pressures.