These blue spark plug wires feature a silicone inner core and outer jacket that keeps the wires flexible while maintaining their color. These wires provide more fire power and up to 10 times less resistance than standard resistor core wires. They eliminate radio frequency interference and are ideal for use with multi-spark discharge ignition systems, electronic ignitions, and on board computer systems. They provide heat protection up to 600-degrees F, come with 135 and 180-degree plug boots, and fit 8-cylinder engines.