This auction is for a Zalman ZM-VE200 SE hard drive enclosure, included a 750GB HDD 2.5" hard drive pre-installed. What makes this enclosure different is the built-in virtual CD-ROM feature. You can download any bootable ISO file (Windows, Linux, etc) and copy it to the iso folder on the hard drive. You can then select the file from the dial on the enclosure and the ISO will be mounted as a virtual CD-ROM. You can then boot any computer with the drive attached and install an operating system from it. No need to for making bootable USB drives.