It is a bundle of wires used for signal communication between the ECU (engine control unit) and devices and for supplying power from the battery to ensure a safe and comfortable ride, and is the most important core circuit of a motorcycle.
A variety of technologies are used to improve the functionality of the product, such as using heat-resistant materials in high-temperature areas near the engine and noise-preventing wires in sensor circuits with weak currents.

A circuit that transmits signals to control the amount of fuel injection and ignition timing of an engine.
It also includes a sensor circuit that detects problems by checking the engine speed and temperature.
With the spread of FI (Fuel Injection) vehicles, higher reliability is required.

Power and ground circuits that supply the necessary power to each piece of equipment in the car body.
The power and ground circuits, which supply the electric power needed for each piece of equipment in the car body, use thicker wires than the signal circuits to allow the flow of larger electric power, a fuse unit is incorporated to prevent short circuits.

A signal circuit that connects each instrument on the meter panel to each device sensor on the vehicle body.
This wiring is for displaying vehicle conditions, such as the speedometer and fuel level.

A circuit that supplies power to headlights and turn signal lamps and transmits signals for changing the direction of illumination.

Power supply circuits for tail lights, blinker lamps, and brake linked stop lamps.