Accel's Power Pulse Coil features greater available spark duration than stock coils. Molded in bright yellow or black impact resistant thermo-plastic compound. This coil is guaranteed to improve throttle response and top end performance on 12 Volt Harley. Works super with Armored Shield Ignition wires. 12 Volt points, Dyna "S" or Prestolite triggered Dual Fire ignitions 1965-1983 use the 5 Ohm coil, 1984 and later models with stock electronic ignition use the 3 Ohm coil.