Precut and have the plug/coil boots and terminals already installed Boots and wires are made from extra-high-temperature silicon, which gives protection up to 600?F Spiro-Pro core provides up to 10 times the conductivity of a standard carbon-core wire Low resistance means they run cooler and last three to four times longer than carbon-core wires Made in the U.S.A.. WIRES SP PRO BLK 18+ ST
