Harness wire is like the neuron system in hummer body. It is used to connect every electronic component and make every single signal to be comprehensive and accuracy act. It stores electrical energy in chemical form in the battery. And it delivers electrical energy from these sources in demand to any electrical component in the vehicle. Sometimes a harness wire could be 7meters for four wheels vehicle to use.Ta Young Electronic also provides variety of length of harness wire and compatible price by custom order.