XJS COUPE / XJSC CONVERTIBLE 1983 > 1992. XJS COUPE / XJSC CONVERTIBLE 1991 > 1996. XJ6 3.2 ( X300 ) 1994 > 1997. XJ6 SOVEREIGN 4.0 (X300) 1994 > 1997. They have a waterproof seal around the spark plug and are resistant to oil, water and under-bonnet corrosive materials.Ignition leads connect the distributor to the spark plugs and therefore form an important part of the overall car engine ignition system.
