Memory Stick
The Memory Stick Duo was developed in response to Sony's need for a smaller flash memory card for pocket-sized digital cameras, cell phones and the PlayStation Portable. It is slightly smaller than the competing Secure Digital (SD) format and roughly two thirds the length of the standard Memory Stick form factor, but costs more. Memory Stick Duos are available with the same features as the larger standard Memory Stick, available with and without high speed mode, and with and without MagicGate support. The Memory Stick PRO Duo has replaced the Memory Stick Duo due to its 128 MB size limitation, but has kept the same form factor as the Duo.