3U Holding AG, together with its subsidiaries, engages in the sale of sanitary, heating, and air conditioning technology products in Germany and internationally. The company operates in three segments: Information and Telecommunications Technology (ITC); Renewable Energies; and Sanitary, Heating and Air Conditioning Technology (SHAC). It provides call-by-call, pre-selection, call-through, and voice termination products; and data center services, such as collocation, infrastructure as a service, and telecommunication services, as well as operates networks and installation facilities. In addition, the company develops, operates, and sells cloud-based CRM and ERP solutions; and trades in IT licenses. Further, it develops wind power projects; and generates electricity with its own power plants using wind and solar energy. Additionally, the company offers sanitary, heating, and air conditioning technology products to wholesalers, craftsmen, self-builders, through its online stores. 3U Holding AG was founded in 1997 and is headquartered in Marburg, Germany.