The Genuine BMW Optical Conductor B-Pillar, part number 63319242155, is a component used in BMW vehicles to transmit light signals between the body of the car and the door. It is located in the B-pillar, which is the vertical support between the front and rear doors. This optical conductor is made of high-quality materials and is designed to ensure reliable and efficient transmission of light signals, such as turn signals and interior lighting, throughout the vehicle. It is a genuine BMW part and is specifically designed for use in BMW vehicles.