It is a SD card adapter. Player can play games in the SD card via Swiss.
The adapter bypasses the limitations of GameCube memory card adapters and allows the use of memory cards larger than 2GB. The maximum capacity of memory card that can be used is dictated by the software being used, currently this is up to 512GB for Swiss, but note that only some memory cards are compatible with Swiss and you should check online to ensure your memory card will work.
– Serial port SD memory card adapter for running homebrew software on a GameCube console.
– Easy to plug and play your SD card.