Memory Stick Pro Duo is a removable flash memory card format. The Memory Stick PRO Duo currently has a maximum size of 16 GB. A 32GB Pro Duo card is due to be released in 2009. Although, theoretically the maximum size could be 2TB (two terabytes), equal to the SDHC limit, but costs are higher than SD.

The Pro Duo is a storage device that offers high speed transfer and instant playback of files.
The easily transfer files from one computer or laptop to another, but Memory Stick PRO Duo is also used with Sony digital compact cameras, digital music players (MP3 Players), PDAs, mobile phones, the PlayStation Portable (PSP), and other devices such as the Sony VAIO range.