In applications such as off-road, marine or other harsh conditions, the MSD Blaster High Vibration Coil is the best choice. This protects the coil’s internal components from high and low frequency vibrations that are commonly experienced in racing. If you are looking to upgrade your stock coil, or want to compliment the performance of your MSD Blaster Ignition, MSD 5, 6 or 7, the Blaster Coil line is the right choice. Our Blaster Coils are designed for improved spark output! Special 100:1 windings are used to provide maximum build-up of voltage! These windings are held secure and kept cool in an oil filled metal canister. The tower assembly is molded of durable alkyd material due to its high dielectric characteristics while wide spaced brass primary terminals prevent the possibility of spark. Each Blaster Coil can be used with a stock ignition, Blaster Ignition, MSD 5, 6 or 7 Ignition Control. Most late model vehicles with electronic ignitions do not require a ballast resistor, check your ignition and manufacturers specifications to determine if a ballast is required in your application. Mallory Unilite applications also require the ballast resistor.