Carquest Premium Secondary Air Filters serve as backups to primary air filters when the primary filter is being replaced during servicing, preventing airborne contaminants such as dust, dirt, and debris from reaching your combustion chamber. Protecting critical engine components from wear and damage helps maintain optimal engine power, improve fuel efficiency, and extend engine life - keeping your equipment performing at its best. Carquest Premium Secondary Air Filters are designed to meet or exceed the performance requirements of the Original Equipment Manufacturer (OEM).