A cabin AC filter (or pollen filter) cleans the air entering your vehicle's interior through the HVAC system, trapping dust, pollen, mold, bacteria, and other pollutants to provide cleaner, healthier air for occupants, preventing allergens and fumes from circulating inside the car. Located behind the glove box, it protects passengers and keeps the cabin cleaner, improving AC efficiency and reducing musty smells when clogged, requiring periodic replacement