When removed from the Amara frame, the cushion includes a sem-rigid face plate with an air outlet opening in it. When reinstalling the Amara cushion onto the mask frame, you'll simply press the air outlet opening over the part of the mask elbow which extends into the interior of the mask frame.
This unique cushion desing makes removing and replacing the cushion quick and easy, and as mistake-proof as possible.
If you're not sure which size mask cushion you need, take a look at the bottom front of your cushion. There should be a size indicator printed on the semi-rigid face plate part of the cushion, just below the air outlet opening. P for Petite, S for Small, M for Medium and L for Large.