At the time the R09 manual was first printed, they were only compatible with SD cards up to 2GB. However, beginning with R-09 OS (operating system) version 1.20, the R-09 is compatible with SDHC Class 2 cards up 8GB (they MUST be SDHC Class 2). For cards under 2GB you will still need to use standard SD cards and not the SDHC Class 2 cards.