Denso Iridium Extended Spark Plug KJ20SR11 / 3378 Replaces ZFR6FIX11 The material Iridium is far superior to platinum, & is actually extracted from meteorites. The metal is 6 times harder, 8 times stronger, & able to take temperatures up to 1200&186;F hotter! The DENSO Iridium center electrode tip is the world's smallest (only 0.4mm diameter) to produce the hottest most concentrated spark, while requiring the least voltage (5, 000 less volts to fire than conventional spark plugs!) For performance or everyday driving, this plug is the one! Low required voltage Better acceleration response & operational stability Lower fuel consumption Longer lifetime DIMENSIONS: Height (mm): 43 Width (mm): 24.5 Length (mm): 85 If you are unsure as to whether this is the correct part for your vehicle, please don't hesitate to contact us. Alternatively please use the cross reference table above.