The Genuine BMW Side-Marker Rear Reflector Left - 63147848451 is a replacement part for the rear side-marker on a BMW vehicle. It is designed to fit on the left side of the vehicle and is a genuine BMW product. The part number for this reflector is 63147848451. It is used to enhance the visibility of the vehicle to other drivers on the road, especially in low light conditions. This reflector is made with high-quality materials and is specifically designed for BMW vehicles to ensure a perfect fit and function. It is an essential component for maintaining the safety and appearance of a BMW vehicle.