I have been using the F30 but have been struggling with the headgear. It's usually ok if I sleep on my left side, only sometimes slips. But on my back, right, or sitting it will slide down from my nose and leak.
Things I tried: using a headband to hold the top back, looping the velco around a pony tail, F20 headgear I already had, talking to my doctor (who basically said one size fits no one), and making my own. Some of these kind of work, but still frustrating.
I don't know why it didn't occur to me before to look for a similar mask, but the AMARA is perfect. They have 2 sizes of headgear and are just different enough to sit in a different spot. I can change position easily and it doesn't move. So just wanted to share for anyone else struggling to make it fit
Standard size: https://www.amazon.com/Amara-View-Headg ... B01JAPLCMU