The Genuine VW / Audi Timing Belt Kit - 178642 is a comprehensive package of products designed for the maintenance and replacement of the timing belt in a Volkswagen or Audi car. This kit includes three essential components: a timing belt, a tensioner, and a water pump. The timing belt is responsible for synchronizing the rotation of the engine's camshaft and crankshaft, ensuring the proper timing of engine valves and pistons. The tensioner helps to maintain the proper tension on the timing belt, while the water pump circulates coolant to prevent the engine from overheating. These components work together to ensure the smooth and efficient operation of the engine. This kit is specifically designed for Volkswagen and Audi cars, providing high-quality and reliable parts for optimal performance and longevity.