In applications such as off-road, marine, or other harsh conditions, the MSD Blaster High-Vibration Coil is the best choice. The sturdy metal housing of the High-Vibration Coil is completely potted with a premium grade epoxy to completely encase the coil's primary and secondary windings. This method of construction is designed to protect the coil's internal components from high and low frequency vibrations that are commonly experienced with extreme driving conditions. To form the spark plug tower, alkyd material was used for its high dielectric characteristics. This special material will not carbon track when high voltage is passed across its surface making it ideal for coil tower applications. The primary coil terminals are made of brass and are spaced far apart to prevent any possibility of arcing to ground.