The R4 Card was the first version of the R4, designed for the Nintendo DS console and later the DS lite console. With the R4 Card users are able to add memory cards called Micro SD cards to their console and connected these cards to their PCs to transfer over files. Once transferred onto the Micro SD card you can insert it into the R4 and then into your console for playback on the go or wherever you like.
The R4 Card was upgraded shortly after its release to the R4 SDHC card, which supported Micro SDHC memory cards, with a capacity of up to 32GB which offers users the ability to store more files. The original R4 supported up to 2GB of data, whereas the newer R4 SDHC now supports up to 32GB.