Mirage Quattro question

I have bunches of 5 year old mirage Quattro masks and all the cushions have an M on the bottom of the cushion. So my question is, "does the M stand for medium"?

Yes, I know this is a dumb question but I have recently been in the hospital mostly unconscious and three weeks in a coma. Now I am having trouble with the new cpap mask I was given so I thought I would try the old ones. Thanks

Yes sir, "M" for medium.