DESC: Pump up the volume wherever you are--whether pounding the urban jungle pavement or power cycling at the gym--with Sony's NW-E105PS Network Walkman. Amazingly small and light, the round NW-E105PS measures just 2.21 inches in diameter and weighs under one ounce. It has a 512 MB internal flash memory and plays MP3, ATRAC, and ATRAC3plus formats. It's also compatible with content purchased and downloaded from Sony's Connect Music Store.