In many performance applications such as off-road, drag race, marine and oval track racing, strong vibration forces can be transmitted through the chassis to the MSD unit. To protect the MSD from excessive vibration, this vibration mounts are an absolute neccessity! They are offered in three different types. One for the 5- and 6-Series ignitions, one for the 7-, 8-, and 10-Series ignitions, and one for the Pro Power Coil.