MicronAir Particle Cabin Air Filter, fits Chevrolet HHR 2006-2010 requires 1 filter, Cobalt 2005-2010 requires 1 filter, Pontiac G5 2007-2009 requires 1 filter, Pursuit 2005-2006 requires 1 filter, Saturn Ion 2003-2007 requires 1 filter. 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.