Q: What does upgradable mean? Can I increase the capacity of my drive?
A: While it is not possible to increase the capacity of your GoFlex drive, the unique and seamless GoFlex cable system transforms the GoFlex, GoFlex Pro, and GoFlex Slim ultra-portable drives into truly upgradable solutions in that you can access the content on your drive with any interface you would like, all by simply selecting the cable that matches your interface of choice. Each drive kit (excluding the drive-only box) comes standard with a USB 2.0 cable for out-of-the-box USB 2.0 performance. However, by simply changing the cable, you can upgrade the speed and performance of your interface to have faster FireWire 800, eSATA, or USB 3.0 transfer rates than that of the standard USB 2.0 drive
This means that many GoFlex devices ship with a USB 2.0 cable. Any USB 2.0 device, including the cable, in the device chain will cause the entre chain to work at 2.0 seeds.
For the A connector, I'm having trouble finding a side-by-side photo showing the differences. The plastic inside will be blue for most 3.0 cables. I'll keep looking... Try http://www.usb3.com/usb3-info.html