Pertronix MC-181 Mercury Marine 8 Cylinder Ignitor Delivers twice the voltage to the spark plugs, increasing horsepower, fuel economy, and spark plug life 2:1 improvement over points in current fall time for increased coil output Rotating cobalt magnets trigger a Hall Effect integrated circuit no points to burn, no moving parts to wear out Epoxy molding makes our module impervious to dirt, oil, grease and moisture Stable timing no need for any adjustments