If you are familiar with R4 or any other flash cart, setting up the R4SDHC is the same. The R4SDHC cartridge size is identical to that of the original R4DS cartridge. The microSD card is inserted through the top of the cartridge and fits flush with the cartridge.
Features:
2nd Generation Storage Device (no booting tool required)
Flush fitting Slot 1 Card
Uses microSD/microSDHC Memory Card (supports memory size up to 32GB), FAT16 or FAT32 File System
Supports any microSD/microSDHC Memory Card speed without lagging 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
Supports 4-scale-lightness adjustment (DS Lite only)
Supports Soft Reset
Supports Moonshell 1.6 Software Reset Function (press START key