AirFit™ F20 Cushion by Resmed. This is the replacement seal for the ResMed AirFit™ F20 Full Face. ResMed’s InfinitySeal™ silicone cushion provides superior comfort, fit, and stability without bruising the nose. It is hard plastic on one side with a silicone seal attached. You can find the size located under the elbow.
FYI-- This cushion can also be used on the AirTouch™ F20 as an alternative to the UltraSoft™ Memory Foam Cushion. The modular frame allows you to interchange sizes too.