... lifetime; 4. IP55 protection; 5. Insulation F 2BHB double stage high vacuum blowers We are professional in air blower/ring blower ... /vortex blower/vacuum pump producing. With more than 10 years' manufacture experience ... : blow, Hoover, exhaust, cool, transport7. Structure:three phase & double stageModel name: 2BHB920-H17Type information:1. frequency(Hz): 50/602 ...