R4i Gold Cards describes

R4i SDHC and R4 SDHC is designed for NDS series host (DSi) and R4i to support the development of SLOT-1 flashcard, is the award-winning R4 flashcard successor. R4i SDHC and R4 SDHC support SDHC specification maximum 32GB Flash memory card, in addition to game programming, self-made program running, and multimedia features, is the ultimate DS player essential peripherals.