NGK performance wires are custom manufactured for your vehicle, all have original equipment identical connections, but are constructed with superior quality cabling. The NGK ferrite magnetic core wire has only 1/2 the resistance of traditional carbon core wires, yet has all the same RFI suppression capabilities. In addition, traditional carbon core wires have a tendency to increase resistance with age while NGK's wire wound ferrite magnetic cables remain virtually unchanged. This means more power to the spark plug to begin with, plus longer life. Oil and high heat resistant (250 deg. celcius) silicone outer jacket.