Amazon.com Product Description
The IBM Microdrive is a miniaturized hard disk drive about the size of a quarter. The Microdrive fits into the CompactFlash Type II slots on devices that require flash memory storage. Generally used in digital cameras, the Microdrive can also be used in other devices that require a large amount of storage. Two caveats about this storage panacea: First, it requires slightly more power than a normal CompactFlash card, so it's not compatible with all devices that have a CompactFlash Type II slot--check your device's owner's manual to be sure. Second, it is a miniaturized spinning hard disk, so it's more fragile than solid-state memory cards. It can be damaged if it is dropped, and it shouldn't be used at extreme elevations or temperatures.