Robust and durable air-cooled vacuum pumps with inner oil circulation, which work after the rotation principle. Oil mist separartors guarantee clean exhaust air. The pumps are furnished with a non-return valve and a vacuum pumps achieve a vacuum of approx. 98 %. The pumps are delivered without oil filling. The oil has to be added separatly. Optionally available with motor protection switch. Surrounding temperature: approx. 12 - 30°C. Operational temperature: approx. 70 - 80°C.