This product is a genuine BMW finisher for the window frame on the top of the rear left door. It is made of aluminum with a satin finish and the part number is 51357317807. This finisher is designed specifically for BMW vehicles and is a high-quality replacement for damaged or worn out finishers. It is durable and will provide a sleek and polished look to your vehicle's window frame. This finisher is an original BMW part and is compatible with other BMW components.