Supplied as shown, the price is for a set (4) spark plugs.
When turbocharging or adding any form of forced induction to an engine, care needs to be taken around controlling detonation of the mixture. As you build more and more power, heat and pressure in the cylinder increases, changing to a spark plug that is ‘one step colder’ reduces the heat at the surface of the spark plug, which can become a hot zone and a cause of detonation.
The stock spark plugs are BRK7E and NGK’s method is the higher the number the colder the spark plug, moving to a BRK7E is the minimum jump required for turbocharging and delivers good results.
These will come gapped to 0.8mm. If you find you need to gap them lower consider upgrading your ignition system with a Coil on Plug (COP) kit.