- R4 3DS Card is a Nintendo 3DS compatible flash cartridge. It enables your Nintendo 3DS or 3DS XL or DSi or DSi XL to accept a micro SD memory card - which in turn means on your 3DS you can watch 3D movie, play music, browse pictures and so much more! What you have in this card is fully customizable graphical user interface, 100 compatible with all NDS rom games, the full support of DSi homebrew and many additional features that work very well.