Features: 1. The breathing trainer reduces the amount of air flow to the lungs, forcing you to take more focused and deeper breaths. The training of breathing against resistance will cause and use oxygen more efficiently, as a result increasing your lung capacity. 2. The lung trainer regulates how much air you take in, trains your respiratory muscles and boosts your stamina in any sport or daily activity. 3. Great for anyone who has poor physical condition, smoking or under lots of anxiety ; stress. Extremely good for athletes, singers, pilots who requires professional respiratory muscle training. 4. Lightweight and designed with soft silicone rubber mouth piece with grip surface. Comes with a portable. Notice: 1.Actual color may be slightly different from the image due to different monitor and light effect 2.Please allow 1-3cm deviation due to manual measurement Description: Teeth Grip: 2.2cm Total Length: 4cm includes: 1xBreathing Exercise Mouthpiece