1.It can start pumping directly from atmospheric pressure. 2.It can be used as a low vacuum pump alone or as a fore pump in combination with other high vacuum pumps. 3.This series of products are widely used in metallurgy, industry, light industry, medicine, electronics and semiconductor industries. 4.The pump cannot be used to pump gases with high oxygen content, toxic, explosive, chemical reaction with pump oil or corrosive to ferrous metals, nor can it be used as a compressor or transmission pump.