Belkin Thunderbolt 2 HD Dock and USB 3.0 Cable Bundle Transfers files at 20 Gbps with Thunderbolt 2 technology 4x faster than USB 3.0 and 25x faster than FireWire 800 Supports dual displays & 4K cinema resolution Super-Speed data transfer up to 5 Gbit/s (USB 3.0 port required for USB 3.0 transfer speeds and features) Molded strain relief and PVC over molding Backward compatible with USB 2.0