The bottom hard rubber part separated from the rest of the sandal. If I didnt, I could tell I was going to get blisters. Super comfy and no problems with the buckles. Even though I forgot to charge it still worked well on next day. Great wear Adaptor is not working how can i claim warranty from appario That help avoid the brain freeze that colder water gives. I really liked it. I?m not a big sneaker person I do purchase them for work but this is the quickest ever replaced a sneaker bc of the peeling material, the sole has poor cushion and it was not comfortable for me. But a soft rubber.