Tri-balls incentive spirometer is a breathing lung exerciser which is a flow-oriented device, provides an indirect indicator "ball" of the patient's inspired volume. It be used to help strengthen respiratory musculature and to help restore and maintain lung capacity by encouraging a slow, deep breathing.Three color-coded balls in each chamber provide a visual incentive for the patient. Air flows into single channel, when it passes through the chamber, it raises each of the three balls depending on the flow inhaled per second.