Model: 520-004
* MP3,WMA playback       
* Plug-and-play USB, U-disk with OS of Windows 98/ME/2000/XP, support Windows and Mac       
* Digital voice recorder       
* Display lyric

Model: 520-018
* Voice recording function
* Supports PCM format with the clear, long time voice recording
* A-B repeats function, easy for learning foreign language Pen function, able to change the pen lead
* Particular MP3 play function without LCD

Model: 520-030
* MP3,WMA playback       
* Plug-and-play USB, U-disk with OS of Windows 98/ME/2000/XP, support Windows and Mac       
* Digital voice recorder       
* Display lyric       
* Multi languages supported (6 kinds language selection)

Model: 520-031
* MP3, WMA playback       
* USB interface, support WINME, WIN2000 and WINXP system       
* Digital voice recorder       
* ID3 tag support with A-B repeat/follow-read/compare-read function       
LCD screen

Model: 520-033
* MP3,WMA playback        
* USB plug: hot plug and play ;Operating system: Windows 98/ME/2000/XP/MAC OS (no driver installation needed over     Windows 98)        
* Digital voice recorder        
* ID3 tag support with A-B repeat/follow-read/compare-read function

Model: 520-041
* MP3, WMA playback      
* USB interface, support WINME, WIN2000 and WINXP system      
* Digital voice recorder      
* ID3 tag support with A-B repeat/follow-read/compare-read function