This wire set contains red ignition wires featuring a silicone inner core which is rated up to 600-degrees F. These wires provide increased fire power to the spark plugs and they eliminate radio frequency interference. They are a must when using a multi-spark discharge ignition system, electronic ignitions, and on-board computer systems. They have low profile, silicone boots with grips and vibration-proof double spring locking spark plug terminals and do not require sleeving.