sony walkman 4gb headphone-integrated nw-ws413 (blue) sony ideal for sports and active lifestyles, this unique digital music player allows you to be wire-free, hands-free, and without distraction whether you’re working out at the gym, playing outdoors or even swimming. ergonomically designed for long-lasting comfort hours on end. along with a wire-free, secure fit the sports walkman is guaranteed to never fall out even during the most rigorous physical activities the nw-ws413 may be compact in size but can store hours of music thanks to the internal 4 gb memory. designed for athletes in all sports, and for use in salt and fresh water up to two meters deep. along with being sweat proof and dust proof the sports walkman is built to endure the toughest training.