The Sony Walkman NWZ-B173 is a digital media player that is calibrated to charge very quickly at the outset, giving around 90 minutes use off a three minute charge, making it accessible and practical. The Sony NWZ-B173 has a 3-line monochrome display, that is used to relay the MP3 player's interface and all track information. Furthermore, it has a built in storage capacity of 4 GB for the user to store his favorite music.