2005 NW-A1000
The NW-A1000 is a Walkman with a hard disk drive, part of the first generation A series.
2013
NW-W273S
The NW-W273S is a waterproof wearable Walkman part of the W series. It has 4GB of built-in storage and supports MP3, AAC, and WMA audio playback formats. It supports approximately 8 hours of playback with a lithium-ion battery.
