Below is a general manufacturer product group description. Please note the information below is not item specific. Item specifics are above in product details.

MSD offers an all new Digital HEI Module and performance coil that will fire up your stock HEI Distributor. The Module is a direct plug-in for the 4-pin HEI module and will produce up to 7.5 amps of current. This increased energy will continue through racing rpm reaching 9,000 rpm!
The Digital Module is extremely accurate in its delivery of this energy resulting in more accurate ignition timing. Another unique feature is an adjustable rev limiter. You can dial in an engine saving rev limit ranging from 5,000-10,000 rpm. The other unique feature of this module is it’s patent pending technology that can detect if an illegal traction control has been installed. For street cars, you’ll never know this feature is there, but for circle track racers that are breaking the rules, they’ll find themselves with a low rpm limit activated! If a traction control event is detected, the Digital HEI module will go into a rev limit mode.
To get the most performance out of the Digital HEI Module, MSD offers a performance Coil as well. This Coil drops right in place of the original coil and fits under the stock coil cover.