Cable 1 is 2-core for the power supply is connected to the power source on the e-bike. This can be the connection cable of the headlight, or a separate connection cable for additional consumers, as many e-bikes have, or the battery itself.
The input voltage range of the indicator box is 6 - 55 volts DC, so it is not suitable for connection to the hub dynamo.
The output is 12 volts for the turn signals.
The electronics of the velorian e-bike indicator set are protected against reverse polarity, so nothing will break if the plus and minus connections are reversed. It simply does not work.
Cable 2 is 4-core and contains the connections for the rear turn signals.
Cable 3 has 10 wires and contains the connections for the front turn signals, the indicator switch and a status LED. The cables on the blinkerbox are replaceable. If you cut too short during assembly, this is annoying, but can be remedied by unscrewing the housing and reinserting a new longer cable.
The blinkerbox has a sound generator that makes the flashing audible. The sound is almost like the ticking of the indicator in a car and is just loud enough to be heard while driving. If you find the ticking annoying, you can switch it off via the indicator box configuration and alternatively mount a status LED on the handlebar.