Ducts and pipes of metal for central heating installations; Ducts of metal for air-conditioning installations; Ducts of metal for ventilating and air-conditioning installations; Ducts of metal for ventilating installations; Ducts of metal, for central heating installations; Metal air conditioning ducts; Metal vent cover for HVAC ducts; Prefabricated aluminum ventilating ducts for installation in residential and commercial garage doors; Ventilating ducts of metal