Elgato Thunderbolt™ Dock has two Thunderbolt™ ports.
2x Thunderbolt™ (10 Gb/s, bi-directional Input/Output)
Elgato Thunderbolt™ Dock: one to connect to your computer, and one to extend the versatility of Thunderbolt™ even further. Connect high-speed peripherals such as the Elgato Thunderbolt™ Drive+ to take advantage of unmatched performance, add a Thunderbolt™ to FireWire adapter for compatibility with your legacy devices, or connect an additional Thunderbolt™ display. You can even connect another Elgato Thunderbolt™ Dock.