The Zimmermann Brake Kit - Front/Rear - 138854 is a comprehensive kit of products designed to improve the braking system of a car. It includes a front and rear brake kit, consisting of brake pads, rotors, and calipers. The brake pads are essential components that create friction against the rotors to slow down or stop the vehicle. The rotors, also known as brake discs, are circular metal discs that rotate with the wheels and provide a surface for the brake pads to grip onto. The calipers are responsible for squeezing the brake pads against the rotors when the brake pedal is pressed, creating the necessary friction to slow down the vehicle.

In addition to these main components, the kit also includes brake hardware, such as clips, pins, and shims, to ensure proper installation and functioning of the brake system. It may also include brake fluid, which is essential for transferring the force from the brake pedal to the brake pads and rotors.

Overall, the Zimmermann Brake Kit - Front/Rear - 138854 is a comprehensive set of products that can significantly improve the braking performance of a car. It is suitable for both the front and rear brakes, making it a complete solution for a vehicle's braking needs.