This little kit allows you to connect a MicroSD card to the Serial Port 2 of the GameCube.
You can use this card with Swiss, so it doesn't take up a memory card slot anymore.
The SD2SP2 is also compatible with the upcoming GCLoader ODE by Black Dog Tech.
Installation is extremely simple, no soldering or opening the console is required. Just plug the MicroSD card into the adapter and then plug the adapter to the Serial Port 2 under the GameCube console.
Please make sure that your GameCube console actually has a Serial Port 2. If it does, you will find it clearly marked on the underside.