Philips FY2420/10 NanoProtect Activated 2000 Series AC2887 and AC2882 Carbon Filter for Air Purifier (Black) Style:Activated Carbon Filter   Unfolded active carbon adsorption area is equal to about 43 football courts which provides consistent protection and a long lifetime up to 12 months.Honeycomb structured active carbon is made for the purpose of effectively removing various gases: incl. harmful TVOC and odors.