Pertronix D170600 Flame-Thrower Plug and Play Non Vacuum Cast Electronic Distributor with Ignitor II Technology for British 4 Cylinder Engine All new lightweight cast aluminum housings Tailored advance curve for optimal performance and drivability Integrated Ignitor II electronic ignition with variable 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.Built in reverse polarity and over current protection shuts down the system, preventing component damage