DESCRIPTION: This multi-stage blower/exhauster can be used for either air pressure or vacuum. It is an alternative to a Roots-type lobe blower or regenerative blower. This model range runs relatively flat performance between about 100 and 1000 cfm. At our 6500 foot elevation and 55 degree F day, we saw about 8 inches mercury vacuum and 7.5 psi pressure with static airflow. Looking at performance curves, you would see better numbers if there was more airflow. We saw the air temperature rise by about 70 degrees. Other similar used units are being sold for over $8000. FEATURES: Manufactured by Hoffman in USAModel 4106C (6 stage?)SN 0786046GS-34119POE-6-28140-125 psi maximum case pressure30 hp 230/460 VAC 3-PhaseVolume to ~1000 cfmPressure to ~9 psi?Maximum Vacuum to ~11"hg?6" flange inlet 3" flange outlet275 degreesF maximum outlet temperature CA Inventory # 5804