This is the replacement cushion for the Ultra Mirage or Ultra Mirage II nasal mask. Any size cushion can be used on the mask frame. For instance, if a large size cushion is too big, a standard size cushion could be installed on the same frame and vice verse.
A shallow cushion is the same size as the standard except it has less of a curve at the bridge area and is designed for individuals with a fairly flat nose bridge.
Shallow-Wide is best used on faces with a fairly flat nose bridge and a wide to very wide nose.