It allows you to read different types of cards (camera or mobile phone) from the front of your PC.
It sits in a free 3.5 '' bay on your computer and connects to a USB port on the motherboard. Supported Ports:
Compact flash I, II / MicroDrive / SD / Mini SD / MMC / RS-MMC / MS / MS Pro / MS Duo / MS Pro Duo / TF / XD / SDHC / M2