Your ear contacts the felt inside the earmuff, which explains why they have ?hygiene kits? to replace them. After I bought the sandals, I checked some of the other reviews on reef sandals and a lot of people said it didnt fit their feet. I?ll be gifting them as a birthday gift to our Granddaughter who will be 11. This is sort of hard to explain but if you have this, Im sure you understand. Easy to install and serves it purpose. So I encourage you to give this book a try. Tried to get the Duet Max in the flame color also but they werent available in my size. It uses Bluetooth 3. Fits perfect and has no issues covering the light or charging hole! Traditional earphones hurt my ears after short term use.