Before the introduction of the euro, francs were also used in France, Belgium and Luxembourg, while Andorra and Monaco accepted the French franc as legal tender (Monegasque franc).
Inside the caliper is a brake pad, a small block of friction material backed with a metal plate. When you step on your brake pedal, pistons inside the caliper cause it to apply pressure to the brake pad which squeezes the rotor, causing the car to slow or stop.
Brake Caliper Piston Products. In disk brake systems, the brake calipers are the ones that squeeze the brake pads against the disk or rotor of a wheel. One of the parts that make this squeezing action possible is the Brake Caliper Piston. When you step on the brakes, the pressure made by the brake booster or the master cylinder pushes the brake fluid through the fuel lines and out of the cylinders in individual wheels.