Mann Filters act like a sponge, the activated charcoal layer embedded in the non-woven material absorbs harmful gases such as nitrogen dioxide, fuels and ozone into pores which are 10,000 times finer than a human hair. That is how the combo-filter ensures a healthy cabin environment. This modern filter consists of a non-woven-based particle filter media, an activated charcoal layer and a carrier media to improve stability. Mann Filter brand name is marketed by Mann Hummel, a leading development partner and original equipment supplier of the international automobile industry since 1941.