Brand x anti pollution filterthe brand x anti pollution filter is a genuine replacement filter for the brand x anti pollution mask it is designed to offer a high level of protection from the inhalation of pollutants that you would commonly find in the city our filtering media has a 95 filtering efficiency and an active carbon layer also helps to filter the bad small particles from the air includes 2x exhalation valves to make breathing easier and reduce hot airwater vapourcarbon dioxide bui