The Continental Timing Belt Kit - 135387 is a comprehensive set of products designed for use in a car's engine. It includes the following contents: a timing belt, a tensioner, and an idler pulley. These components work together to ensure proper timing and synchronization of the engine's internal parts, allowing for optimal performance and efficiency. The timing belt is responsible for connecting the engine's camshaft and crankshaft, while the tensioner maintains proper tension on the belt to prevent slipping or misalignment. The idler pulley helps guide the belt and keep it in place. This kit is essential for maintaining the smooth operation of a car's engine and should be replaced periodically according to the manufacturer's recommendations.