4GB Micro SDHD Memory cards. Guanateed to work in your R4 DS, R4i SDHC and our R4 3DS Cards. Get the benefit of buying a micro sd card that has been tested and works flawlessly with your R4. Our low prices and flat rate shipping means you won't have any headaches or hassles - just a 4GB memory card that you know will just work! Class 4 Micro SDHC 4GB Card.