OnStar Corporation is a subsidiary of General Motors that provides subscription-based communications, in-vehicle security, hands-free calling, turn-by-turn navigation, and remote diagnostics systems throughout the United States, Canada, China, Mexico, Europe, Brazil and Argentina. A similar service is known as ChevyStar in Latin American markets (except in Mexico, Brazil and Argentina). In September 2011 the president of OnStar stated that the service had more than six million customers. A new aftermarket interior rear-view mirror with a built-in OnStar module, branded as OnStar FMV, became available to the public on July 24, 2011. It provides some of the features an OEM system has, such as Automatic Crash Response, Stolen Vehicle Tracking, Turn-by-Turn Navigation, and Roadside Assistance. The OnStar service relied on CDMA mobile phone voice and data communication, primarily via Verizon Wireless in the United States and Bell Mobility in Canada, as well as location information using GPS technology. AT&T announced the contract to replace Verizon in 2013 based on 4G technology from 2014. Drivers and passengers can use its audio interface to contact OnStar representatives for emergency services, vehicle diagnostics and directions.