Air-conditioning ducts, not of metal; Downspouts not of metal; Ducts, not of metal, for ventilating and air-conditioning installations; Non-metal air-conditioning ducts; Non-metal air conditioning ducts; Non-metal HVAC ducts; Non-metal ventilating ducts; Non-metal water pipes; Plastic conduit for drainage; Rigid pipes of polypropylene for the supply of drinking water and heating and air conditioning systems in houses, office buildings and industrial buildings; Rigid pipes, not of metal; Rigid...