Champion – Copper Plus – Spark Plug fit for 1948-1974 Big Twin

• Copper Plus spark plug has a copper core center electrode that allows for accurate control of heat range, optimizing performance and longevity of the spark plug
• Patented SAC-9 semi-conductor resistor for maximum EMI and RFI suppression
• Patented Ultraseal coated shell for rust prevention

Thread Reach: 3/8″ / 9.5 MM

Hex Size:20.6 MM / 13/16″

Heat Range: 12

Gap: .25″