Feature: 1. Enhance Strength: Breathing trainer can enhance breathing strength and control performance, improve your anaerobic threshold and push your limits. 2. Improve Endurance: Using a breathing trainer can improve the strength and endurance of the breathing muscles, which can increase the limit of exercise. 3. Easy Use: Breathe in slowly through your mouth, as deep as you can. Hold your breath for a few seconds. Slowly exhale through your mouth until completely exhaled. 4. Daily Use: Breathing lung exerciser can effectively improve lung function and prevent respiratory diseases, do 10‑15 times to complete a set. Do 2 to 4 sets a day. 5. Wide Application: Deep breathing lung exerciser is small in size for easy to carry, which can be used for adults, seniors, children, swimmers, athletes, singers, etc. Specification: Item Type: Breathing Exerciser Material: Silicone Application: Wide range of applications, can be used for adults, the elderly, children, swimmers, athletes, singers and so on.. Package List: 1 x Breathing Exercise Device1 x Manual Card