The Genuine BMW Expansion Tank - 17137640515 is a high-quality replacement part for BMW vehicles. This expansion tank is designed to hold excess coolant and maintain proper pressure in the cooling system. It is made from durable materials and is an exact fit for specific BMW models. This expansion tank is an essential component for the proper functioning of the vehicle's cooling system and helps prevent overheating. It is an authentic BMW product and meets all the necessary specifications and standards. This expansion tank is easy to install and is a reliable choice for maintaining the performance of your BMW.