Compact unit for vacuum operation with RB-DV air injection vacuum blower, which makes it possible to reach a high compression ratio by means of a patented atmospheric air injection device ROBUSCHI that reduces overheating of the gas and the power absorbed by the blower. The unit maintains all the innovative characteristics of the ROBOX evolution: silence, compactness and easy maintenance. ROBOX evolution /DV in the ATEX version available on request.