This is the replacement cushion for ResMed AirFit™ N30i Nasal Mask. The cushion features a slight curve, which is designed to provide a comfortable, stable seal that is less obtrusive.  This cushion is only compatible with the N30i, it is not compatible with any other mask.

The cushion is available in 4 different sizes, which will all fit the N30i mask frame.
An easy color-coded guide helps to determine which size is needed.
Small has a red circle with "S"
Medium has a blue circle with "M"
Small-Wide has a purple circle with "SW"
Wide has a gray circle with "W"
 
Mask Fitting
You can print your ResMed AirFit™N30i Mask sizing guide here (N30i Sizing Templete). Remember to print to scale, as you’ll have to cut out your guide from the document you print.