USB 2.0 Type A Female to Dual Type A Male For Extra Power Y Cable - 20cm
If you have a power hungry USB device that a single USB port can not feed this is the solution for you.
Connect your power hungry device (i.e. an external 2.5" hard drive) to the female USB Type A connector. Then connect the 2 USB Type A male connectors to 2 different USB ports.
The thick Type A male cable provides power and data from one USB port. The thin Type A male cable provides power only from another USB port.