1) MX4SIO (Memory expansion For SIO) is an adapter for the PlayStation 2 that lets you connect SD cards to the memory card slot.

2) The MX4SIO can not replace a memory card! Since it is only an adapter and not a converter to make an SD card into the PS2 memory card.

3) The SD Card is not recognized by the console directly. Only specially developed homebrew software can access the SD Card, although the software is currently in the development phase