I have a similar device. The device itself will show up as a single pseudo-scsi device (e.g. "/dev/sda" or "/dev/sdb", depending on how many things are on your USB bus). The media itself should show up as a partition on that device.
You can "fdisk -l /dev/sda" (or whichever "/dev/sd" device it is) and
see the partition table.
Guus. -- A.J. Bonnema, Leiden The Netherlands, user #328198 with the Linux Counter