The RD 90 filter range offers the lowest breathing resistance due to the increased diameter. It suits the X-plore 4790 mask only.

A1: protection against gases and vapours from organic compounds - B1: protection against inorganic gases and vapours (e.g. chlorine, hydrogen sulfide, hydrogen cyanide) - E1: protection against sulfur dioxide and hydrogen chloride - K1: protection against ammonia and organic ammonia derivatives Filter class 1 offers low protection and has a maximum permissible contaminant concentration of 0.1 Vol% (1000 ppm). - P2: particles up to concentrations of filter class 2: 94 % efficiency - marking R: for use during several work shifts - marking D: dolomite dust testing additionally passed