Product details:

There are two ways to limit your rpms. The rough way simply cuts off ignition spark, which can cause backfiring, extreme engine roughness, and possible engine damage. The gentle way is with these MSD Soft Touch rev controllers. They use sophisticated computer circuitry to drop spark one cylinder at a time, until your engine is at or below its maximum rpm. Those cylinders are then fired on the next cycle, to prevent them from loading up with fuel. The result is smooth rev limiting action without all the rough stuff. There are two versions of the Soft Touch rev controllers--one for MSD's 6T, 6TN, 6HVC ignitions, and one for OEM electronic and points ignitions. Both come with 6,000, 7,000, and 8,000 rpm plug-in modules, and can be used with other modules or MSD's RPM module selector.