This B&H Kit includes a Thunderbolt Express Dock and a black, 3' Thunderbolt Cable. The Thunderbolt Express dock allows you to connect a variety of devices to your computer/laptop. It features three USB 3.0 ports, two Thunderbolt ports, one FireWire 800 port, one Gigabit Ethernet port, one 3.5mm headphone output jack and one 3.5mm audio input jack. The Thunderbolt cable provides a reliable way to connect high performance data devices to high resolution displays, as it features both PCIe and DisplayPort.The cable also allows you to transfer full length HD movies in under 30 seconds or back up a year of continuous MP3 music in a few minutes. The dock is compatible with Mac OS 10.8.3 or higher with Thunderbolt port.