The brake light is generally installed in the rear of the vehicle, the main color of the red light, enhance the penetration of the light source, so that the vehicle behind even in the case of low visibility, easy to find the front vehicle brake, to prevent rear-end accidents. A simple model is the power supply through the insurance, and then to the brake switch, when the brake pedal is pressed to brake, the switch is connected, electricity is sent to two brake lights and a high brake light there, through the negative line and the car body is connected to form a circuit.