Brake caliper is a kind of caliper device with the function of decelerating, stopping or maintaining the stop state of the moving wheel, which is generally only used for disc brake system. Four pistons, six pistons means that there are four brake cylinders and six hydraulic pistons in use. The more pistons in the brake caliper, the more stable and flat the brake force.

The working principle of disc brake can be described as a plate. When holding the rotating plate with thumb and index finger, the plate will stop rotating. The thumb and index finger play the role of brake caliper.

The disc brake on the car is composed of a brake oil pump, a brake disc connected with the wheel and a brake caliper on the disc. When braking, the high-pressure brake oil pushes the piston in the caliper to press the brake shoe against the brake disc to produce braking effect. Disc brake, it is divided into ordinary disc brake and ventilated disc brake.

The ventilation disc brake is to reserve a gap between two brake discs so that the air flow can pass through the gap. Some ventilation discs also drill many circular ventilation holes on the disc surface, or cut a ventilation slot or prefabricated rectangular ventilation holes on the disc surface.

The air flow is used in the ventilated disc brake, and its cooling and heating effect is better than that of the ordinary disc brake. The main advantage of disc brake is that it can brake rapidly when braking at high speed, and the heat dissipation effect is better than drum brake. The stability of braking efficiency is good, and it is easy to install advanced electronic equipment like ABS.