Size: 104 * 35 * 21mm; material: ABS; speed: 5Gbps; not used for charging, used to provide more USB to transfer files.
The power supply specification is 3.5 * 1.35mm 5V 1A, and supports hard drives smaller than 1TB. If the hard drives are larger than 1TB, the power supply is not suitable for you.
There are 9 options in this link, if you want to use USB 3.0 with power, please select the correct option you need.
The power supply can solve the problem of insufficient power supply. If you need to use a hard disk, you should choose a power supply. Please note that do not use more than two hard disks at the same time.
The power supply can increase the transmission speed of the usb, and the insufficient power supply will reduce the data transmission and the error code. The power supply can improve the reliability.