Copper is a commonly used conductor in vehicle wiring systems. Copper wiring may consist of a single extruded wire coated with plastic insulation or multiple thin strands of braided and bound wire coated with insulation. Braided or stranded wire has greater flexibility and due to something known as Litz effect can conduct slightly more current. Flexibility is a desirable characteristic in vehicle electrical systems so braided wire is used almost exclusively. The resistance to current flow in a section of copper wire will depend on its sectional area (wire gauge), temperature, and overall length; the greater the sectional area of copper wire, the less resistance to current flow. Quite simply, thicker electrical wire provides a greater area for flow and is, therefore, less restrictive. This is because more free electrons are available in heavy-duty wire gauge than in a thin gauge. For instance, 8-gauge wire is thicker than 16-gauge wire. So 8-gauge wire is capable of permitting greater current flow than 16-gauge wire. In most vehicle applications, wiring is designed to be as thin as possible while being capable of handling the electrical load it is designed for. Wire gauge is usually original equipment manufacturer (OEM) specified to handle the intended electrical load plus a small safety margin.