Pertronix 91665A Ignitor II Electronic Ignition Module. The Ignitor II has many of the same great features that the Ignitor has, but its smarter. Ignitor II units sense the coil current level and use a powerful micro controller to adjust the dwell. Variable dwell helps to maintain peak energy throughout the entire RPM range. Ignitor II systems develop up to 4 times more energy between 3000 and 5000 RPM than standard ignition systems. High RPM performance is improved when used with the Flame-Thrower II super low resistance (0.6 ohms) 45,000 volt coil. Adaptive dwell maintains peak energy throughout the entire RPM range, reducing misfires while improving engine performance. Develops on average 4 times more available energy between 3000 and 5000 RPM, and 2 times more available plug voltage. Peak current level is reached just prior to spark for maximum energy without the heat build-up, increasing coil and module life. Never Change Points Again! Adjusts spark timing at higher RPMs to compensate for the inherent electronic delay. Senses startup and develops more energy for quicker, easier starting. Built in reverse polarity and over current protection shuts down the system, preventing component damage. Guaranteed for 30 months!