Sony NWZ-B183F B183F Flash MP3 Player with Built-in FM Tuner (4GB) - Black Sony Walkman MP3 player with built-in USB with aluminium finish Distinctive design 4GB Storage Media of Memory Size capacity - the equivalent of 900 songs Storage Media Rechargeable battery life lasts up to 20 hours, 3 minute quick charge for when you're in a hurry Bass Boost function for low-end power, Crystal clear OLED display 3-minute Quick Charge What's In The Box !!! NWZ-B183-Sony Headphones-Quick Start Guide,