Yes it is an electrical thing that adjusts your headlights. It is located on the right side on the headlight switch. You can choose option 0 for one passenger or option 1 for two passengers and backs in the trunk. The adjustment is for a better driving by night. If you sit in you car with a passengers and back in the trunk then the car is in the back deeper as in the front. Then the headlights will shine more in the Air but you want the light on the street and not in the air. Then you choose option 1 and the headlights go down and the light is on the street and not in the air. If you drive alone then you choose option 0 and the headlights goes up and you see more in front of the street. Hope that will help you.