The Corteco Cabin Air Filter Set (E39) - 21651897 is a replacement filter set for the cabin air system in a vehicle. It is specifically designed for use in the E39 model and is made by the brand Corteco. This filter set includes all the necessary components to effectively filter the air that enters the cabin of the vehicle, providing clean and fresh air for the passengers. This product is essential for maintaining good air quality inside the vehicle and should be replaced regularly for optimal performance.