I mentioned earlier I didnt think the book was too helpful. pure and undulated camel dung! Really not sure how to proceed - but thats another topic. While I was waiting on the employee to do something, I was walking around, looking at the phones, tablets, etc. of all the reef range I find these ones the most comfortable, on my third pair now, They are very comfortable to walk in. Comfort and fit:So for me, the default EarWings were the perfect size for me, and I shifted down to the smaller EarTips because the medium size was a bit too much over a long period of time. Convient bien au maintien des coupe-congères (cutting edge) de petites souffleuses. The only downside is long term use comfort. After a while the cushion does move and it is hard to get them back to the side.