ResMed AirFit N20 masks are in three sizes – Large, Medium and Small. You need to choose the size of the mask before ordering one.

You can also measure your nose width with a ruler. Match your nose measurements (in mm) corresponding to the following sizes:

• Small: 23-37 mm
• Medium: 30-45 mm
• Large: 45-55 mm

ResMed has introduced a measurement board to easily choose your mask size. You may download the AirFit N20 measurement board and follow the instructions.

1. Ensure that the board in printed to scale. Cut the measurement area along the dotted line.
2. Stand in front of a mirror and hold the sizing guide to your face.
3. Try fitting your nose into each sizing option – Large / Medium / Small
4. The most comfortable match will provide you with the best fit size.