DeVilbiss's Vacu-Aide Suction Pump has high performance capabilities in a small, compact respiratory aid. The vacuum has an adjustable flow regulator, changed with an easy-to-turn knob. The knob has a safety lock feature that wont allow the knob to be twisted off. The adjustment allows 80-550 mm Hg and a free flow of 27 LPM. The suction pump's gauge is easy to read and located conveniently on the pump. The actual figures may vary based on altitude, barometric pressure changes and system configuration.