R4 ds feature:

-2nd generation storage device (no booting tool required) ;
-Flush fitting slot 1 card ;
-Uses MicroSD card, FAT16 or 32 ;
-Supports any MicroSD card speed with no lag in game ;
-Supports Clean ROM, drag and drop. Works on any OS ;
-Built in NoPass ;
-Automatically detect save type ;
-Save directly to MicroSD card, not to onboard chip ;
-Supports Moonshell and other homebrew. Open I/O interface ;
-User friendly skinnable interface. Touchscreen or button operation ;
-Supports rumble pak and memory pak ;
-Supports the WiFi game, DS Rumble Pak, DS Browser;
-Supports changes of the background of Operation Interface;
-Support Skin DIY by setting background and font colors on Main Menu and Game Menu manually and automatically;
-Supports 4-scale-lightness adjustment ( DS Lite only );
-Supports the Soft Reset;
-Supports Action Replay cheat ;
-moonshell 1.6 support Software Reset function( Press START key back to the R4 menu).

Package including:
1x R4 DS Card (Slot-1)
1x Kingston 2GB micro sd

Official download website:
http://www.r4ds.cn/