On May 19th, 2015, Chairman Sun Yunchuang, the UNITED Compressor founder, visits Hitachi in Japan together with other high management. They are friendly and warmly welcomed by related Hitachi chairman. The conference held in Hitachi headquarters in Tokyo focused on developing energy-saving and environmentally friendly products, particularly the high-energy-efficiency two-stage air compressors. Besides, the two companies agree on developing high-reliable automobile oil-free scroll compressor to keep up with the fast development of low-carbon buses.