I thought I would not be able to fly again. I had a flight that resulted in terrible vertigo, a roaring in my head that lasted hours and general malaise. Saw this product and tried them on a short one hour flight. Worked perfectly. Used them on a longer, 3 hour flight this year. No problems. They work exactly as described. Fun to watch the cabin pressure rise and fall on the app. It even tells you when to put them in, and when you can remove them.