-- Comfy and durable materials. Bottom is well made-thick rubber, so they support your feet a little better than thin flip flop types. Apple Devices work great but I just can’t figure out the drivers for windows. The speaker works either by receiving a broadcast from a Bluetooth connected device, or by using a 3. Lovely fit, very comfortable and stylish. I did plug them directly into my computers sound card. I think it would be 5 stars if there was a way of keeping out the smaller rocks and beach pebbles that fall inside, but I think that is a problem with any beach shoe. Worth it and reasonably priced. Have had some people say they couldnt hear me properly when outside talking to them, but this isnt a main usage for me. The outside of the cord is braided, which is a nice touch.