JSER Black USB 3.0 Female to Dual USB Male Extra Power Data Y Extension Cable for 2.5" Mobile Hard Disk Does one USB port not supply enough power for your USB device? ;Our Sync USB 3.0 Power Adapter Y cable for your is the solution.Our cable allows for power to be taken from 2 USB ports, like a PC and External hard drive. Black USB 3.0 Female to Dual USB Male Extra Power Data Y Extension Cable for 2.5" Mobile Hard Disk;Two USB male connector,One is for USB 3.0 power and data, another one for USB 2.0 power only. Allows you to link 1 USB device into 2 USB Ports on your PC for more power.There are times you may have an external device, such as a portable 2.5 hard drive, and a standard USB cable is not able to transfer enough power to operate the device.;This problem can be easily solved by using this USB 3.0 y Cable Length: 30cm