The cushion size is printed on the hard section of the cushion below the round opening. The size is indicated in circle with a white letter (S, M, or L).
Evolving cushion technology:
The InfinitySeal for the AirFitF20 Full Face Mask is designed with variable thickness for more comfort and stability. It adapts to the unique facial contours of each person, so you can be confident of obtaining a secure and comfortable mask fit. Within the cushion are 7 different contours and comfort points with varying thickness to unsure a unrivaled comfort stable fit.