WACKER silicone rubber grades can be used at temperatures up to 250 °C for long periods and briefly up to 300 °C. Their high tear resistance ensures that the ignition cables are not damaged during repair or if abraded against edges in the engine compartment. High voltage of 40 kV is preferably insulated using silicone rubber grades with high electrical breakdown resistance. Special conductive silicones serve as the conductors in the ignition cables.