This coolant reservoir radiator expansion tank is designed for use with 325, 325e, 325es, 325i, 325is, and 528e models equipped with 2.5L or 2.7L engines.The part number 17111707540 is referenced for compatibility verification.Constructed from plastic, the tank withstands operating temperatures up to 105℃.The design aims to prevent leaks and maintain proper coolant levels within the vehicle's cooling system.This component serves as a direct replacement to restore cooling system function.Installation follows standard procedures for the specified vehicle models.Users should confirm part number 17111707540 matches their existing component before purchase to a correct fit.