The Rein Engine Coolant Reservoir Kit (528i 525i 530i) - EPK0015 is a high-quality replacement kit for BMW 528i, 525i, and 530i models. It includes a durable plastic coolant reservoir, a cap, and all necessary hardware for installation. This kit is designed to effectively store and regulate the engine coolant, preventing overheating and potential engine damage. It is a direct fit for the original equipment and meets or exceeds OEM specifications. This product is a reliable and cost-effective solution for maintaining optimal engine performance and longevity.