In-Check Oral is a portable hand-held inspiratory flow meter that provides an assessment of the speed of inhalation. The In-Check Oral measures inspiratory flow between 30 and 350 L/min, inspiratory flow is thought of by physicians as a sensitive marker for COPD screening. The In-Check Oral works when a patient inhales through the mouth, this will cause air to be drawn through the meter and a cursor moves along the scale to indicate the speed of inhalation.