You listen to music while you train on dry land, so why shouldn't you be able to move to the beat underwater as well? This X-1 Interval swim solution features a waterproof case designed to house a 4th generation iPod shuffle and integrated Surge 2G headphones that deliver a clear, rich sound. Submersible in up to 12 feet of water, it has loops for easy attachment to any pair of goggles and push-button controls for volume and playback.