6
Rigid metal air ventilation ducts; rigid metal air ventilation channels for use as ducts; flexible metal air ventilation ducts; flexible metal air ventilation channels for use as ducts; structural parts and fittings therefor
11
Air ventilation systems including for buildings, underground car parks, or tunnels composed of air conditioning, air cooling and ventilation apparatus and instruments; air ventilation system extractor fans; air ventilation system exhaust fans; air ventilation system silencers; structural parts and fittings therefor including air ventilation system connectors, air ventilation system mounting brackets, and air ventilation system connecting brackets; air ventilation systems for vehicles, ships, or aircraft composed of air conditioning, air cooling and ventilation apparatus and instruments; air exhaust systems for vehicles, ships, or aircraft composed of air conditioning, air cooling and ventilation apparatus and instruments; structural parts and fittings therefor
19
Non-metallic rigid air ventilation ducts; non-metallic rigid ventilation channels for use as ducts; non-metallic flexible air ventilation ducts; non-metallic flexible ventilation channels for use as ducts; structural parts and fittings therefor