MMCs are currently available in sizes up to and including 32 GB. They are used in almost every context in which memory cards are used, like cellular phones, digital audio players, digital cameras and PDAs. Since the introduction of Secure Digital card and SDIO (Secure Digital Input/Output) slot few companies build MMC slots into their devices (an exception is some mobile devices like the Nokia 9300 communicator, where the smaller size of the MMC is a benefit), but the slightly thinner, pin-compatible MMCs can be used in almost any device that supports SD cards if the software/firmware on the devices support them.
The MiCard is a backward-compatible extension of the MMC standard with a theoretical maximum size of 2048 GB (2 TB) announced in 2007. The card is composed of two detachable parts, much like RS-MMC. The smaller card fits in a USB port while the larger version fits in traditional MMC and SD card readers.