IMR9C-9H - NGK Spark Plug Sparkplug - Type : Laser Iridium - IMR9C9H No. 6777 Genuine NGK Spark Plug (Complete Cross Reference numbers below) PLUG SPECS.. Spanner Size : 16 mm Thread : M10 Thread Length : 19mm Secondary Thread Length : 12.7mm Secondary Thread Length : 6.3mm Top Connection : Threaded Top (M4) Spark Projection : 2.15mm Iridium Centre Electrode 1 Single Earth Electrode Seat Type : Gasket Washer Each Sale is for 1 Plug - Simply enter the Quantity you need. You can check you plug requirements on NGK's PARTFINDER