Increased performance with World's smallest Iridium Center Electrode (0.4mm).

• No-compromise, top of the line race spark plug for the most serious enthusiast.
• Patented U-groove ground electrode design fires leaner mixtures than conventional plugs
• Precision machine-rolled threads reduce seizing and cross-threading in delicate aluminum heads
• Wide range of part numbers for thousands of applications, including classic and collector cars
• Lasts twice as long as most conventional plugs
• Withstands temperatures greater than 4000° Fahrenheit