These coils feature advanced bobbin technology, highly specialized silicone magnetic steel cores, along with optimized winding, resistance and turns ratios to delivery 10-15 percent more energy than the OEM coils. Specialized high temperature epoxy resists shock and vibration, while increasing thermal conductivity. These are direct plug replacements for OEM coils. They feature bodies and, or secondary towers molded in ACCEL yellow and feature brass secondary contacts (except direct fire coil on plug applications).