Features: brand new and high quality Soft silicone mouth piece with grip surface, reduces the amount of air flow to the lungs, forcing you to take more focused & deeper breaths. The training of breathing against resistance will cause and use oxygen more efficiently, as a result increasing your lung capacity. The lung trainer regulates how much air you take in, trains your respiratory muscles and boosts your stamina in any sport or daily activity. You can easily adjust the resistance for valve to select your desired level of breathing or resistance. Turn the for valve to reduce & increase resistance. Great for anyone who has poor physical condition, smoker, athletes, singers, pilots who requires professional respiratory muscle training. Specifications: Material: Silicone/ABS Color: As The Picture Shows Package Weight: approx.41g Size: approx.10x5.5x3.5cm/3.9x2.17x1.38in Package Includes: 1Pc x Lung Fitness Trainer note: Please allow 1-2cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!