Core Material Copper - Delivers efficient heat transfer for stable ignition and reliable performance. Thread Size 5/8 inch - Fits engines that specify a 5/8 inch spark plug thread; provides secure seating and consistent torque. Top Material Type Iridium - Iridium tip offers high durability and reliable ignition across a wide temperature range. Key benefits - Reliable ignition under various driving conditions thanks to the iridium tip. - Longer tip life reduces maintenance frequency for demanding or high-mileage use. - Copper core supports effective heat management to help prevent misfires and fouling. - Compatible with engines designed for a 5/8 inch thread for straightforward replacement. Compatibility and usage - Designed for engines that require a 5/8 inch threaded component; verify vehicle manual or existing plug size to confirm fit. Use scenarios - Daily driver replacement: swap worn plugs in a modern gasoline car that requires 5/8 inch thread for improved ignition reliability. - Performance or high-mileage engine: use where long service life and consistent spark performance are prioritized. - Classic or vintage car maintenance: suitable for engines using 5/8 inch thread plugs, offering durable iridium tip performance.