Regarding the question, you are having. The two are extra I/O basically it's one Digital Input and one digital output.
For more details you can try visiting this link: RUTX11 Input/Output - Teltonika Networks Wiki (teltonika-networks.com)
I hope it helps
Kindly check the said links below, you can use this kind of power cables:
Automotive Power Supply | Teltonika Networks (teltonika-networks.com)
4-way Power cable | Teltonika Networks (teltonika-networks.com)