The black PS40 Performance Ignition Coil is designed to enhance the output of factory ignition systems and fits in place of most stock canister coils. Thanks to its lower resistance and optimized turns ratio, it produces a higher outer spark when used with breaker points, amplified ignitions or with the FAST® XR-I Points Replacement system. The coil reliably delivers a high output spark through 6,500 RPM on mild street performance applications and is oil filled to keep the windings cool. It is supplied with a ballast resistor, which is required if you plan to fire up your original breaker point-style ignition system.