Get more spark from your plugs with a set of Speedmaster ignition wires. These 10.5mm wires feature high-temperature 100% pure silicone insulator outer layer! Their spiral-wound copper conductor has extremely low resistance combined with extremely high EMI suppression. In plain terms, these wires deliver the highest possible energy to the spark plugs so that your ignition upgrades reach their full potential, without creating interference for onboard electronics. The wires have a high dielectric strength insulator and heavy glass braid, topped with heavy-duty black silicone jackets and high-temperature black boots to resist damage from heat and abrasion.