WiFi Max Router Power Input Voltage

[cruz123]

I have installed a new WiFi Max Router using the supplied power supply and cable.  I need a longer cable and note that there is a second input power supply port - a conventional centre pin arrangement.  However there is no indication of the required voltage.  Is it 12V?

[cruz123]

No one can help?

here's a pic of the back of the new sr213, as you see no voltage given over the power in port.