Two ""NEW"" Champion Marine Spark plugs L77 JC4 (821-1) (Resists rust &
corrosion) Same as NKG B7HS10... Used in Outboard motors such as Evinrude,
Mariner, Mercury, Johnson, Yahama, Etc... Threads 14mm, Thread Reach 12.7mm,
Seat Type = Flat, Hex = 21mm,,, $5 each...