MicronAir Particle Cabin Air Filter, fits Chevrolet Venture 1998-2000 requires 2 filters, Oldsmobile Silhouette 1998-2000 requires 2 filters, Pontiac Montana 1998-2000 requires 2 filters, and Trans Sport 1998-2000 requires 2 filters. 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.