The Hondata Coil Pack Retrofit (CPR) allows the use of 'coil on plug' individual ignition coils on engines with distributor based ignition systems (D, B, F and H series Honda engines). It does this by replacing the stock coil and ignition with an electronic circuit which can drive igniter type individual ignition coils, such as used on later model Honda engines. A Hondata S300 system and US OBD1 ECU are required.