LOW NOISE--- Low noise level due to slow R.P.M. and well lubricated. 50~70dB * HIGH PRESSURE--- High pressure due to vane-attachment and oil-sealed effect. * LESS VIBRATION AND PULSE--- Less vibration and pulse due to slow R.P.M. and well balanced rotor. * LONG ENDURANCE AND EASY MAINTENANCE--- Longer endurance due to solid structure and easy maintenance. * ENERGY SAVING--- Energy saving due to efficient structure resulting high pressure and capacity.