CY USB 3.0 Female to Dual USB Male Extra Power Data Y Extension Cable for 2.5" Mobile Hard Disk Black Color 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.(No data for USB2.0 port 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. 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