Sport MP3 Wireless Wrap-Around Headphones / Headset with Built in 2GB MP3 Player. (Includes USB Cable) Supports MP3 & WMA music files Built-in 3.7V 8 hours battery life Frequency response: 20Hz-20KHz. Signal-to-Noise &gt;80db. Speaker Power: 2X10 mW Supported by Windows 98/ME/XP/Vista/Windows 7, Linux 9, and Mac OS X Memory of 2 GBholds up to 500 songs (approx 4 min per song) Supports MP3 WMA music files