The Zimmermann Brake Kit - Rear - 138648 is a comprehensive set of products designed specifically for a car's rear brakes. It includes three essential components to ensure optimal performance and safety: brake pads, rotors, and hardware. The brake pads are responsible for creating friction against the rotors, which helps to slow down and stop the car. The rotors, also known as brake discs, are the circular metal discs that the brake pads clamp onto. The hardware includes all necessary bolts, clips, and other small parts needed for proper installation and functioning of the brakes. This kit is essential for maintaining the rear brakes of a car and ensuring smooth and efficient braking.