Convert contact breaker ignition systems to electronic ignition. Consisting of an optical switch and separate power module together with a fitting kit (purchased separately) for your distributor model. Systems is fully compatible with Lumenition and Micro Dynamics Rev Limiters and shift lights, and are completely maintenance free. Precise & accurate electronic switching improves engine smoothness & performance. Easier starting. Fixed dwell gives higher performance from existing coil under all conditions. Improves the operation of old or worn distributors. Recommended on up to 8 cylinder engines at 9,000 rpm. Suits distributors with advance mechanism above base plate such as AC Delco.