YOu canuse4 ,at the sametime.
Built-in high-speed chip, you can use keyboard/U hard disk at the same time.
Save your data safely,Built-in diodes can repair multiple circuit protection.
fast transmission,Work and entertainment without delay and no lag, fast,transfer of large files,High-speed transmission.
With a power interface, if you need to connect a large-capacity hard drive, you need an Android data cable + charger to supply power.