Two SATA drives can be stacked in the internal drive cage, they simply slide into the connectors located at the rear of the housing. Screws are provided to attach them securely to the sides of the cage.
The driver/software CD contains a universal USB driver for Windows 98 users, if there are any still out there. There is also a software component called PC Clone EX that enables the one-touch backup button on the rear of the housing. Unfortunately it seems that the software is not compatible with Windows Vista. ** UPDATE ** There is a new version of the software that is Vista compatible, located Here. Under the software section, there is a file named "IB-3218/-3220/-3221 PcClone (Vista compatible)".
In testing, the IB 3218 yields around 33Mbps throughput, which is about the most that can be expected with USB connectivity. Both drives appear as individual volumes in Windows Explorer; there is no option to merge the disks into one volume such as with drive spanning.
Let's wrap things up with some final thoughts and conclusion.