Restores and maintains lung capacity in post operative patients by slow, synchronized deep breathing. Allows visual calibration and estimation of the patients progress. Strengthens primary and accessory respiratory muscles and conditions them. Enhances endurance of both inspiratory and expiratory muscles. Improves respiratory parameters. Improves maximal exercise capacity. Improves cardio-pulmonary status of the patient, enhancing the overall fitness and wellbeing. Increases circulation of hormones in the blood which increase the blood blow to the heart, brain and lungs. Improves oxygenation of blood, reduces fat levels by burning calories. Assists pulmonary rehabilitation in patients with COPD, improves the quality of their life. Sustained deep breathing has been shown to relieve anxiety and fight stress.