To meet today's air quality standards, many manufacturing processes now require that the air be filtered before its released back into the atmosphere. This type of machinery is commonly seen on all kinds of factories, especially around areas where dust and dirt or solvents and chemicals may be released. The air filtration systems work like huge vacuum cleaners to trap these materials and remove them. This HO Scale model adds a modern touch to any big factory and includes a variety of ductwork, simulated filtration machinery and three large exhaust stacks.