It doesn’t have USB or FireWire, so the My Book Thunderbolt Duo can be used only with Thunderbolt Macs
With its two Thunderbolt ports, the My Book Thunderbolt Duo easily fits into a Thunderbolt daisy chain. The other major difference is that the My Book Thunderbolt Duo, as the name indicates, has Thunderbolt connectors-two of them, to be exact.
Western Digital’s My Book Thunderbolt Duo is about as big as WD’s My Book Studio II, and the two drives have similar cases, The obvious difference are the different activity indicator lights on the front of each drive.
