Conquer USB power limitations with the USB 2.0 B Male to 2 USB A Male Y-Cable from Cables To Go. Perfect for transferring enough power to operate an external device, such as a portable 2.5" hard drive. Simply plug this cable's USB B end into the device and the two USB A ends into open USB ports on a single PC or Mac. The cable then pulls power from both USB ports, increasing the output to the external drive.