3-lobe Roots Blower 1, 100% Oil-less operation 2, Quiet, Compact 3, High performance 4, Maintenance free Specifications: Wide range for air volume pressure Capacity: 0.6 ~ 236 m³/min Pressure: 1000 ~ 8,000mmAq Features: Constant pressure and air flow. Cast IronClean air not with oil moist. Construction simple and easy maintenance. Bearings are all ed by oil moist. Three Lobes Roots Blower