The SR 597 A1BE2K1 gas filter is intended for use in the SR 500/SR 500 EX fan. The filter type protect against the following gases/vapours: Type A protects against organic gases and vapours, such as solvents, with boiling points > +65 C. Type B protects against inorganic gases and vapours, such as chlorine, hydrogen sulphide and hydrogen cyanide. Type E protects against acidic gases and vapours, such as sulphur dioxide and hydrogen fluoride. Type K protects against ammonia and certain amines, such as ethylene diamine. The SR 500/SR 500 EX fan unit must always be used with two particle filters or two combined filters consisting of gas filters and particle filters. About- Gas filter offering respiratory protection against organic vapours with boiling points above 65C, inorganic vapours, acid gases and ammonia For use with the Sundstrm SR 500 and SR 500 EX powered respirator units Parts should be checked regularly for signs of wear and damage, and replaced when necessary Specificatio