Philips NanoProtect Active Carbon Filter for Series 6000 Purifier removes odour and various gases. Double deck of active carbon filter provides doubled performance on removal odour and various gases. Double performance Double deck of filters provides double performance Mixed active carbon for various gas removel Impregnated carbon process in Japan Various gas removal Mixed active carbon for the purpose of various gases removal with Japan technology inside: 50% coal cokes based active carbon (CC-AC), 50% coconut shell based active carbon and Impregnated carbon process in Japan, targets various gases removal rather than 1 gas type: Coconut palm based AC is consist of Micro pore, which is good for removing gas with small molecular, but coal based AC is consist of Meso pore, good for gas having big molecular.