Ductwork and ducting in the nature of heating, ventilation and air conditioning ducts, pipes, and parts of ducting systems, namely, pipe couplings, elbows for pipes, pipe joints, pipe collars, duct and pipe connectors in the nature of reducers, end caps for pipes, and pipe connectors, all made wholly or principally of metal; structural parts and fittings therefor made wholly or principally of metal; all of the aforementioned goods being products developed to target high efficiency systems that are being designed to conform to environmentally friendly building initiatives by reducing leakage which creates higher efficiencies leading to lower fuel costs