... base 2.uction muffler 3.fety valve, check valve 4.ressure gauge,Lubricating oil 1.Using advanced spiral back into the exhaust ... and therefore, the output air is clean, free of grease.4. High precision, hardened gears, so that further increase machine life ... :1.General base2.uction muffler3.fety valve, check valve4.ressure gauge,Lubricating oil