Ultra Clean Holdings through its subsidiaries, manufactures and supplies production tools, modules, and subsystems for the semiconductor capital equipment industry. The product range includes precision robotic solutions, gas delivery systems, a variety of industrial and automation production equipment products; subsystems that include wafer cleaning subsystems, chemical delivery modules, top-plate assemblies, frame assemblies, and process modules. Its customer base includes firms in semiconductor capital equipment industry, medical, energy, industrial, flat panel and research equipment industries. Its principal markets are North America, Asia, and Europe. Its largest end market by revenue is the United States.