We Greatech is specialized in producing of: (A) Tri. Lobe Roots Blower Bore: 40 to 400mm (1.5 to 16 inch) Air: 0.1 to 280 m3/min Pre: 0 to 2000 mBar As Vacuum: up to -500 mB Air cooled type / Water cooled type Silent type / Vacuum type One stage type / Two stage type Enclosure (B) Silent Roots Blower Bore: 40 to 150mm (1.5 to 6 inch) Air: 0.1 to 22 m3/min Pre: 0 to 600 mBar As vacuum: up to -500 mBar Advantage: Extremely low noise Power saving Oil changing: Once a year Fully cooling, no heating Space saving No need belt No neet foundation plateform. Especially suitable to install in Hospital, School, Hotel, Housing Area, Building... where is prohibit noise. By wooden case.