Copper has excellent characteristics as an electrical current conductor; conversely it is very susceptible to corrosion and oxidation phenomena. For this reason the core of the copper spark plug wire undergoes a galvanising process.

The copper core is covered with a silicone sheath which acts as an insulator as well as making it more physically sturdy.

The silicone rubber outer insulation can resist high temperatures and the corrosive action of petrol and oil.

This type of copper spark plug wire does not have its own resistor, but the resistance is obtained by using suppressor fastenings.

The resistance of the copper wire can vary between 1 and 6.5 kΩ.