The key and the only ingredient of RevoCa Bag series is Revotropix Paulownia biochar. This amazingly powerful Paulownia biochar contains substantially larger amount of micropores and cavities compared to other types of charcoal. These millions of tiny pores and cavities give a larger surface area to adsorb impurities from the air. When air passes through the biochar micropores, odor, allergen, bacteria, pollutants and impurity particles are trapped on the surface, achieving incredible air purifying effect and leaving you fresher and cleaner air naturally without involving any chemicals.