SPARK PLUG
NGK3951 TR55
FOR VOLVO PENTA AND MERCURY/MERCRUISER

Thread Size: 14 mm
Thread Pitch: 1.25 mm
Resistor Value: 5K Ohm
Reach: 18mm (.709″)
Hex Size: 5/8″ (16 mm)

Center Electrode
Material: Nickel

Ground Electrode
Material: Nickel