The Genuine VW / Audi Spark Plug Kit - 178591 is a comprehensive kit designed for servicing the spark plugs in a car. It includes a variety of products to ensure proper maintenance and functioning of the spark plugs. The kit contains spark plugs, which are essential components of the ignition system that provide the spark needed to start the engine. It also includes spark plug wires, which connect the spark plugs to the ignition system. Additionally, the kit contains a spark plug socket, which is a specialized tool used to remove and install the spark plugs. Other items in the kit may include a spark plug gapping tool, which is used to measure and adjust the gap between the spark plug electrodes, and dielectric grease, which helps to ensure a secure connection between the spark plug and the ignition system. Overall, this kit provides all the necessary components for properly maintaining the spark plugs in a car.