One of Central Europe's largest mobile phone operators, Polska Telefonia Cyfrowa (PTC) has more than 13 million subscribers to its voice and data services. Core wireless service is sold under the Era brand, while its prepaid services, primarily targeted at the youth market, are sold under the Tak Tak and Heyah brands. Business clients are served by its Era Biznes unit. The company also provides wireless multimedia content under the Era Omnix banner. German telecom giant Deutsche Telekom owns 70.5% of the company and another 22.5% under its T-Mobile (UK) subsidiary. PTC introduced its service in 1996.