Music is the essential thing when you are in the gym, running or walking. It is usually seen that you can use such gadgets up above the water only, which means that for athletes like swimmers, things are not that fun. But, the Finis Duo seems like solving it with the underwater MP3 device that can give you up to 60 hours of music time. The mechanism of this MP3 is pretty unique. It transfers music by vibrating with your skull and sends out music that sounds just like it sounds on land. The device can work over the 10 feet and helps you in swimming with your favorite podcast, music or book.