A quick and easy to follow video guide to which R4 DS Card you need depending on which Nintendo DS or 3DS system that you have. The full line of R4 and R4i Cards listed with compatibility by system. Regardless of the hand held system you have, there's an R4 DS for the best homebrew games and applications and multimedia playback. All you have to do is make sure you buy the one that is compatible with your console to avoid hassles and headaches!