1. The clearance lamp function allows others to judge the width of your car at a distance at night. It will light up as soon as the clearance lamp or headlamp is turned on;
2. It is also a brake light. When you step on the brake, it will light up to remind the vehicles behind to avoid rear collision. When the clearance light (also this red) is on, it will obviously light up when you brake, which also plays a reminder role.