For the uninformed, the product is designed so that you can used an internal 3.5-inch hard disk drive as an external HDD for the Xbox One. The Data Bank is attached to the top of the system. It connects to the console through the URB port in the back while a dedicated power cable is included to help power the 3.5-inch HDD. The LED indicator will tell you when the Xbox One is accessing the hard drive.
The Xbox One comes with either an internal 500 GB or 1 TB hard drive that can’t be removed. Fortunately, Microsoft will let you add more space through an external storage solution. If you have a 3.5-inch internal HDD lying around, then you might want to take a look at the upcoming Nyko Xbox One Data Bank.
With that said, you are better off getting an external hard drive (like the Seagate 2TB Game Drive for Xbox One, which you can check out here) if you don’t already own a 3.5-inch HDD.