The 8.5 mm "Super Conductor Wire Sets" feature a special helically wound core that has just 40-50 ohms of resistance per foot. That is the lowest resistance of any helically wound wire. To accomplish this, MSD uses a copper alloy conductor due to its great voltage carrying capabilities. The low resistance results in less loss in spark energy so more reaches the spark plug. The conductor is wound extremely tight around a special center core. So tight in fact, that there is over 40 feet of conductor wrapped into a single foot of plug wire. This winding procedure, combined with a ferro-magnetic impregnated center core, produces an extremely effective Electro Magnetic Interference (EMI) "choke". This choke, or suppression capability, keeps the EMI inside the wire where it cannot interfere with other electronics on your vehicle. The outer sleeve that surrounds the conductor assembly is just as impressive. A proprietary blend of silicone and synthetic material produce a sleeve that is highly resistant to high heat as well as abrasion and tears. Sets with 90° boots come with the spark plug terminal and boot installed with the other end open. Distributor cap boots and terminals are included so you can cut the wire to the desired length, then install the terminal with the supplied Mini-Stripper-Crimper.