I love Keens but these just didn?t work for me so I returned them. I often buy Merrells or Alegria, 8. Here there seems to be a language issue. and I had one email communication with their service about the comfortableness I am going to mention below. One of my favourite crocs flat. Its not the cheapest model out there, but I think I got my moneys worth for the $200 I paid. The maximum volume these provide seems adequate and not damage my ears. There are several sized ear buds that We can choose for the comfort. Any shoes would hurt at that point. Its use is straight forward.