The VOLDYNE 5000 Volumetric Exerciser has been scientifically designed to encourage you to perform lung exercises. It allows both of you to see your progress toward improving your inspiratory volume. Deep breathing exercise has been shown to be vitally important to your respiratory fitness. Deep breaths are necessary to reach and expand the small air sacs of your lungs. The VOLDYNE Volumetric Exerciser measures the volume of air you inspire and shows you how effectively you are filling your lungs with each inhalation.