The Genuine BMW Lock Button (Chrom) - 51218399243 is a chrome-plated button designed for use on BMW vehicles. It is used to lock the doors of the vehicle, providing a secure and convenient way to secure the vehicle when not in use. The button is an authentic BMW part, ensuring high quality and compatibility with the vehicle. It is a durable and stylish addition to any BMW and is essential for proper functioning of the locking system.