The Sony NW-WS413 Sports Walkman Digital Music Player is designed for active users. This headset features a unique ergonomic design that fits comfortably around your head and frees you from being tethered to another media player. It's equipped with 4GB of internal flash memory and supports MP3, WMA, AAC-LC, and L-PCM audio files, so you'll have plenty of music to score your workout. To accommodate all active users, the NW-WS413 was designed to be water and dustproof, and to operate in extreme temperatures. Supporting its waterproof design, the NW-WS413 comes with a set of swimming earbuds you can use when you're in the pool.