The Sony NW-WS623 is a robust MP3 player that will last through anything. It's waterproof and dustproof and can withstand extreme temperatures from -5 to 45°C. The player will last for 30 minutes 2 meters underwater in both salt and fresh water. You can go swimming with it in the pool or in the sea. You can wirelessly stream music from your smartphone via Bluetooth. Answer calls, change your walking route, or manage your music with the included Bluetooth remote, which can be attached to your finger or wrist. The MP3 player has 16GB of internal memory, so you can listen to music without needing your smartphone. It has a 12-hour battery life, and only has to be charged for 3 minutes for 1 hour of music, thanks to the quick charge function.