Cabin Filters absorb up to 100% of all pollen, dust particles and harmful substances. This results in a noticeable improvement in the air quality inside the vehicle. Activated Charcoal Filters go one step further than Particulate Filters. Activated Charcoal Cabin Air Filters have a 5-layer design that includes an additional carbon layer that absorbs toxic and foul-smelling gases such as ozone, nitrogen oxide, sulfur dioxide and hydrocarbons, and an additional cover layer for extra protection.