1Clear Scale: This lung rebreather has a clear scale, which makes training more motivating and more adaptable to the exercise needs of the elderly. 2Increase Respiratory Strength: Enhance respiratory strength and control performance. Training your anaerobic broadening and push your limits. Increase oxygen intake and maintain endurance. 3Postoperative Use: Used to help improve the depth and duration of breathing after abdominal or thoracic surgery, to help improve respiratory function, restore lung function, and reduce and prevent postoperative complications. 4Portable Device: The lung breathing trainer is retractable blowing tube, easy to carry does not take up space. With this device, you can perform your training routine wherever you are. 5Wide Range of Applications: This product is suitable for strengthening respiratory muscles, increasing lung ventilation, improving coughing ability, helping to remove sputum, reducing surgical complications, preventing pulmonary atelectasis, etc.