Denso GK3-1 Iridium Saver Industrial Spark Plug Replaces RC78PYP, RC78PYP15DENSO Iridium Saver Spark Plugs are a range of high efficiency, long-life spark plugs for gas engines that use Iridium technology to increase plug life and performance. The term Saver implies the reduction in maintenance costs achieved by the extended plug life in high pressure, lean-burn engines.The Iridium alloy pad (developed and patented by DENSO) is located on the centre electrode. A platinum pad is located on the ground electrode. The two pads help to provide excellent wear resistance compared to conventional spark plugs. Highly reliable monolithic resistor Powder sealing Hot lock Special Nickel plating with better corrosive resistanceITEM SPECIFICS: Thread: 14 mmHex: 16 mmReach: 19 mmGap: 0.3 mmIf 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. Disclaimer: We have taken every care is taken in putting together lists of suitable vehicle compatibilities and component cross references, they are given for general guidance only, and they do not constitute any contractual term, representation or warranty and as such the supplier ( The Green Spark Plug Co LTD ) do not accept any responsibility in respect of any claim whatsoever and howsoever caused arising from the publication of this listing. It remains the responsibility of you (the customer) to check the specification of this item and carefully compare to your original before ordering/installing.