Mallory’s series of PROMASTER Ignition Coils are designed for today’s specialized ignition requirements. PROMASTER Ignition Coils are engineered for faster rise time and longer spark duration for increased performance. The rugged, glass-filled polyester case, along with oil filled construction, assures long life and no energy losses due to arcing. Choose the PROMASTER Coil from the descriptions below. The RPM figures are approximate and may vary depending upon the type of ignition used and state of engine tune. All PROMASTER Coils include brass contact terminals and a spark plug type secondary post for better coil wire retention.