SAE International (Society of Automotive Engineers) and the European Automobile Manufacturing Association (ACEA) proposed the Combined Charging System (CCS) standard in 2011. CCS combines the existing J1772 standard connection for Level 1 or Level 2 AC-powered EV charging with a two-pin connector for up to 350MW of DC-powered fast charging. Seven automotive manufacturers (Audi, BMW, Daimler, Ford, General Motors, Porsche, and Volkswagen) agreed to adopt the combined plug standard, with the first prototype implementation demonstrated in May 2012.