I have a G-Tech 4TB G-RAID Thunderbolt drive. It is connected from one of the Thunderbolt ports on my iMac to one of the two Thunderbolt ports on the G-RAID drive. All works well. I want to daisy-chain the G-RAID to a LaCie USB 3.0 drive (i.e., connect a cable from the second Thunderbolt port on the G-RAID drive to the USB 3.0 port on the LaCie drive). So I need a Thunderbolt to USB 3.0 cable. Does such a cable or adapter exist? I do not want to buy a dock. Thx