China Mobile Limited, an investment holding company, provides mobile telecommunications and related services primarily in the Mainland China. It offers various services comprising local calls, domestic long distance calls, international long distance calls, domestic roaming, and international roaming. The company also provides voice value-added services, including caller identity display, caller restrictions, call waiting, call forwarding, call holding, voice mail, and conference calls; data services, which primarily include short messaging, wireless application protocol, multimedia messaging, and color ring services, as well as Java Applications, interactive voice response, PIM, and others; and mobile reading, mobile gaming, mobile video, mobile mailbox, mobile market, and Internet data center services. In addition, it offers telecommunications network planning, design, and consulting services; roaming clearance services; technology platform development and maintenance services; and mobile data solutions, and system integration and development services, as well as operates a network and business coordination center. Additionally, China Mobile Limited sells mobile phone handsets and devices. As of December 31, 2011, it served approximately 650 million customers. The company was formerly known as China Mobile (Hong Kong) Limited and changed its name to China Mobile Limited in May 2006. China Mobile Limited was founded in 1997. The company is based in Central, Hong Kong, and is considered a Red Chip company due to its listing on the Hong Kong Stock Exchange. China Mobile Limited is a subsidiary of China Mobile Hong Kong (BVI) Limited.