NGK ZFR5F Spark Plug NGK V-Power spark plugs offer reliable performance and improved ignitability over standard nickel plugs. Actual OE or equivalent replacement spark plug. Part Number ZFR5F Resistance 5000 Ohm Ground Electrode Core Material Nickel Center Electrode Core Material Copper Pre-Gap Size 0.32 Hex Size 58 Insulator Height 50.50 mm Seat Type Flat Interchangeable with Mercury 33-8M0204728 33-8M0057936 Fits most Mercury EFI 4-Stroke engines 65 HP - 150 HP California Residents WARNING Can