Product features: 1. High efficiency and environment protection. 2.World famous brand compressor are adopted ( copeland , hitachi, sanyo ), eer up to 5.0, reduce co2 emission to protect earth. 3.Top quality parts are used, compressor, sanhua 4-way valve, emerson valve. 4.Multiple protection function: high pressure, low pressure, overheating, overload anti-freezing, phase sequence, discharge temperature, suction temperature and so on. 5.Cooling only or cooling and heating for optional. 6. Heat recovery function for optional. 7. Wide range for application.