ignition wire sets and Coil-on-Plug boots, the Autolite® brand has the right ignition products for you, regardless of your vehicle make or model. Autolite 4275 Spark Plug Copper Core, Necked Down Center Electrode, Nickel Plated Shell Features: • Product Type: Non Resistor • Heat Range Chart Location: C7 • Hex: 13/16"" • Reach: 3/8"" • Resistor/Non-Resistor/Suppressor: Non Resistor • Seat: Gasket • Thread Diameter: 14MM • Tip: Power • Principal Applications: HARLEY DAVIDSON (ATV's) AERO MARINE, BARR, BERKLEY, CHEVROLET, CHRIS-CRAFT, EMPEROR, EVINRUDE, GRAYMARINE, HARDIN MARINE, JOHNSON, LEHMAN ECON-O-POWER, MARINE REPOWER, MERCRUISER, PALMER-GREENWICH, REVLEY, UNIVERSAL, VOLVO PENTA, XTERMINATOR (Inboard/Ster"  (less)