Denso Iridium Tough Spark Plug VT16 / 5621 Replaces TR5AI-13 ITR4A15 BPR5EFIX13PIridium Toughs lifespan of at least 100,000 km is the result of its combined iridium and platinum design: Iridium Tough plugs feature DENSOs unique 0.4mm Iridium centre electrode, and a traditional ground electrode with a platinum wafer tip. Superb ignitability Low required voltage Better acceleration response and operational stability Lower fuel consumption Longer lifetimeDIMENSIONS: Height (mm): 40 Width (mm): 24.5 Length (mm): 85If 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.