This is a vintage package of 8 Champion F-9Y spark plugs, with a thread diameter of 18mm and a hex size of 13/16". The spark plugs are made of nickel and have a factory finish. They are suitable for gasoline engines with a voltage of 6 or 12 volts. The package contains other part numbers, manufacturer part numbers, and OE/OEM part numbers, all of which are Champion F-9Y spark plugs. The spark plugs are standard configuration and have not been modified. They are a great addition to any vintage car or truck. The box is not in great shape, but these are still  factory sealed.