The Vaico Breather System Kit - 138156 is a comprehensive set of products designed to service and maintain the breather system of a car. The kit includes various components such as hoses, valves, and filters that are essential for the proper functioning of the breather system. These components work together to regulate the air flow in the engine and prevent any buildup of pressure or contaminants. The kit also includes a breather cap, which is responsible for maintaining the correct pressure in the system. Additionally, the kit contains a breather tube, which helps to direct the flow of air and prevent any leakage. Overall, this kit is essential for maintaining the health and performance of a car's breather system.