The seat belt stop button, also referred to as a seat belt stopper, is a tiny but crucial element of a vehicle’s seat belt system. Despite its size, this component plays a significant role in ensuring the seat belt remains functional and easy to use. What Is a Seat Belt Stop Button? The stop button is located on the seat belt strap, near the latch plate—the metal tongue that clicks into the buckle. Its main function is to keep the latch plate from sliding too far down the strap. By securing the latch plate in an accessible position, the stop button ensures the seat belt is always within easy reach, saving time and preventing frustration when fastening your seat belt