1.usb 2.0 or usb 3.0
choose 3.0 if you want to transfer faster. there is no requirement on this election 2.0, the price is similar, personal recommendations to choose 3.0, after all, the computer usb port is now standard usb3.0.
2.whether with power supply
if you buy the hub to connect to print into, mobile hard drives and other high-power devices, it must choose the usb hub with power supply, the supply voltage can be sufficient, these high-power devices to play a role.
3.whether with otg function
if your phone with otg function, want to use this hub phone to read the usb flash disk or connect the mouse button and other equipment, then pick with hub otg function, the phone can become a computer that way.