"There is a compartment on the bottom side of the Hiyatek CF-6159-1 cooler between the two fan openings. Opening a sliding door reveals a storage area for the included USB power cable which has two full size connectors on the end intended for your notebook computer, while the end intended for the cooler has a single mini USB connector. In some situations it may be necessary to have both connections plugged into the host computer to make sure that enough power is provided and that data can be transferred through the hub connections, but I found that using just one USB connection was more than adequate on my notebook computer."