The skilled tuner can use spark plugs to find the source of the problem determine air-fuel ratios, and increase vehicle performance. , determine air-fuel ratios and higher vehicle performance. NGK spark plug has a heat rating; lower numbers suggest a hotter variety, while higher numbers indicate a cold type.NGK Laser Iridium spark plugs provide superior ignitability and long service life. The tip ground electrode has a slow wear rate of the fine wire platinum electrode. Key Features Trivalent metal plating gives excellent anti-corrosion and anti-seizing properties Crumpled ribs prevent flashover Pure alumina silicate ceramic insulator provides ultimate strength and improved heat transfer Copper core support in heat removal Triple seals avoid leakage Specifications BRAND: AUTOWARES SKU:86-6748 UPC:087295067482 Weight:0.15 LBS Thread Diameter14mm Thread Pitch1.25mm Reach19mm (3/4") Hex Size5/8" (1 Material of center electrode: Iridium Ground Electrode: Platinum