ResMed has re-engineered the second generation Quattro. Introducing the Quattro FX Full Face Mask with comfort in mind. The overall size and design is ideal for side sleepers, with a clear line of sight and fewer points of contact to the face. The Quattro FX comes with Spring Air technology that enables the cushion and frame to be responsive and flexible, while providing a solid base for the cushion to seal properly. Some of the best features from the original Quattro have carried over.