A compressor is a device that increases the pressure of a substance (usually a gas) by reducing the volume of the substance. Compressors are used in many applications, most of which involve increasing the pressure inside a gas storage container, such as Compression of gases in petroleum refineries and chemical plants, Storage of gas in high pressure cylinders, Cabin pressurization in airplanes, Air storage for underwater activities and Filling tires. http://www.nuzhuoasu.com/compressor/