C5TF Turbo Plug manufactured by Novarossi. This turbo designed plug, a Novarossi patent, seals at the bottom of the plug instead of at the gasket. This seal takes the threads out of the combustion chamber volume thereby improving performance. Standard and turbo plugs are not interchangeable. Turbo plugs They require a Turbo Head.
Sold in cards of 5 plugs.