The Zimmermann Brake Kit - Rear - 138431 is a comprehensive set of products designed to service the rear brakes of a car. It includes three main components: brake pads, brake rotors, and brake wear sensors. These parts work together to ensure safe and efficient braking performance for the vehicle. The brake pads are responsible for creating friction against the rotors, which helps to slow down and stop the car. The brake rotors are circular discs that the brake pads press against, creating the necessary friction to stop the vehicle. The brake wear sensors are designed to alert the driver when the brake pads are worn and need to be replaced. Together, these products provide a complete solution for maintaining and servicing the rear brakes of a car.