What is the button with an 'a' and a circle in a car?

[StMariana]

Car button with an 'a' and a circle is the auto-hold function of the car. Press once to turn on the auto-hold function, and press again to turn it off. This button is mostly located on the vehicle's center console, placed next to the electronic parking brake. The auto-hold function is an extension of the Electronic Stability Program (ESP), which controls the four-wheel brakes through the ESP. In this process, the ECU computer uses sensors installed on the vehicle to obtain the levelness of the car body and the torque of the wheels, thereby determining whether braking is needed to prevent rolling. The braking force applied to the wheels is not too strong, just enough to stop the vehicle from moving, so that when the accelerator is pressed again to move forward, there won't be too severe jerking.