pipes, ducts and stacks for heating, cooling and ventilating systems, and parts therefor--namely, plenums, elbows, angles and takeoffs, trunk end caps, dampers, starting collars, reducers, increasers and adapters; stack and register adapters, dampers, boots and heads; furnace pipes, furnace pipe drawbands, flue thimbles, wedge connectors, casing collars, tee and wye flues, wye branches, and perimeter fittings, insulated and uninsulated ceiling diffuser boxes; sleeve insulation, draft diverters and hoods; spin fittings for metal ducts and duct boards; exhaust and fresh air hoods; button lock round pipes; flexible fiberglass ducts; black stovepipes; dryer vent hoods, pipes, hoses, collars, and clamps; oval galvanized pipes; cold air drop ducts; and drip pans