Description: Secure Digital Card - removable, rewritable, non-volatile storage medium with a capacity of 256 MB, also suitable for Palm M500 and M505. Read with a suitable adapter in the PC or notebook. Unlike Multimedia Cards (MMC) are Secure Digital Cards (SD Card) slightly thicker, have a write-protect switch, equipped with two additional ports for faster data transfer and have additional security features that the encryption of data for hardware support be Digital Right Management uses (eg rights to protected data such as MP3). SD cards are backward compatible with the MMC.