Sony NWS23 Network Walkman 256 MB Digital Music Player 256 MB of flash memory; holds 4 hours of MP3 and 8 hours of WMA files (CD quality) Sport-oriented player weighs 2 ounces and measures less than four inches long Armband-style carry case Compatible with content from Sony Connect Music Store Powered by 1 AAA battery for up to 70 hours of use; connects via USB 2.0