<p>Champion Copper Plus spark plug technology began as an automotive OE plug, and today is widely used in a variety of power equipment applications. The nickel alloy center and ground electrode provide good wear characteristics and the extrusion of copper into the center electrode allows for an increase in conductivity and heat control. Champion Copper Plus spark plugs are a great choice for OE-replacement on older automotive engines, lawn and garden applications and similar engines. Resistor : Yes Electrode Type : OEM Electrode Core Material : Nickel Copper Alloy Electrode Tip Material : Nickel Copper Alloy Insulator Type : OEM Thread Size (IN) : 0.551 Inch Thread Size (MM) : 14 Millimeter Reach : 0.441 Inch Seat Type : Tapered Wrench Diameter : 5/8 Inch Quantity : Single</p>