Our optional "Tiger Tails" Spark Plug wires have a high heat Silicone jacket as well as our Hy Heat Silicone Spark Plug boots. The "Tiger Tail" Yellow jacket is 7mm, and has a solid core copper strand wire that is tinned for corrosion resistance. Top performance and current under hot under hood temps. Left bank and right bank wires. Don't forget our heavy duty tune up parts and high voltage dual Coil too!