Porta-King manufactures modular and prefabricated building systems from its headquarters in Earth City, Missouri. Since 1969, the company has designed and built in-plant offices, guard booths, modular cleanrooms classified to ISO standards, modular wall partitions, equipment enclosures, mezzanines,

Space Concepts, Inc. is a consultant specializing in mezzanine systems, modular in-plant buildings, modular cleanrooms, and vertical lifting systems for Arizona's industrial, commercial, warehouse, manufacturing, healthcare, aerospace, and retail sectors. Operating in Gilbert and serving the entire