MicronAir Particle Cabin Air Filter, fits Infiniti I35 2002-2004 requires 2 filters, I30 2001-2003 requires 2 filters, Nissan Maxima 2000-2003 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.