PUR exclusive enhanced HVAC filters up to 99.7% of dust, pollen and contaminants . PUR exclusive honeycombed weaves are USA-engineered to last up to 15,000 miles, 25% longer than standard performance of 12,000 miles . PUR filter use thick, industrial strength electrostatic media to trap even the tiniest of particles while densely packed 3-Stage filtration avoids gases and odours from entering the cabin . Designed with 3 premium layers of filtration: dirt filter for road debris, sterile electrostatic filter to block pollen, microscopic particles and an activated carbon layer adsorption filter to soak up exhaust fumes . Contains purified-soda that cleans the outside air flowing through the ventilation system