MicronAir Carbon Cabin Air Filter, fits BMW 5 Series 1997-2003 requires 2 filters. Offers the same filtration as the particle filter plus the added protection of carbon for odors and smells. Traps Harmful pollutants before they reach your vehicle's interior and provides cleaner air for allergy and asthma sufferers. Vehicle manufacturer recommends filter be changed every 6 to 12 months.
