Chemical preparations in the nature of filtering materials used in air conditioning, ventilating and heating; carbon and carbon-based preparations for use in the manufacture of air filters

Filters for use in cleaning or cooling air for engines and parts and fitting therefor

filters for respiratory masks; respiratory masks for industrial use

Air filters for air conditioning, ventilating and heating units; holding frames for air filters used in air conditioning, ventilating and heating installations; housings for air filters used in air conditioning, ventilating and heating installations; parts and fittings therefor

Installation and maintenance of air filtration apparatuses

Design of air filtration apparatuses for others; design of air filters for others