Japanese Performance and Reliability !Iridium spark plugs, made in Japan by G Reddy & NGK Two grades colder than standard Compatible with : see list below Ideal for sporty and tuned Japanese engines Thread length : 19 mm Total length : 72 mm (exc. electrode)Thread : M14x 1.25Socket size : 16G Reddy part no. : 13000068Sold individually, adjust quantity in the shopping cart G Reddy Iridium Tune JIS#8 Spark Plug Specifications Made in Japan by G Reddy, these cold spark plugs have been specifically designed to operate at higher temperatures, helping to disperse heat inside the cylinders. This improves combustion, overall performances and engine reliability, reducing the risk of knocking. Particularly adapted to sporty and tuned Japanese engines or for intensive use, they are fully compatible with the following engines : Toyota : 4A-GE, 4A-GZE (Corolla, MR-2...)Nissan : CA18DET (S13)RB20DE, RB20DET (Skyline R32, Laurel...)RB26DETT (Skyline R32, R33, R34 GT-R)Mazda : B6-ZE, BP-ZE (MX-5 NA & NB)As well as certain European models : Audi, BMW, Porsche, Renault, Volkswagen...