The SK-3501 2TB U3 External Hard Drive. 2TB hard drive is included with this enclosure. The enclosure connects to either Windows or Mac systems via an USB 3.0 port. The SK-3501 U3 has an all-aluminum shell that can to be stacked with another SK-3501 U3 to save space. Cooling the hard drive is done without the need for a noisy fan and is accomplished with a large heatsink located on the bottom of the drive. A power adapter and a USB 3.0 cable are included with the enclosure.