Highly Effective - Offers the widest range of inspiratory/expiratory resistance levels to meet anyone's needs. From low resistance for respiratory rehab patients, gradually increasing to a high resistance level for competitive athletes. Improves endurance, breath holding and shortness of breath. Easy To Use - Only one moving part. Turn the valve to the left to decrease the air flow in order to create more resistance and turn it to the right for the less. Very Compact, only 4" tall - You can take it anywhere and use it anywhere (Pocket Sized). Extremely Comfortable. The flexible medical grade silicone mouthpiece is extremely comfortable, providing excellent fit and seal. Once in your mouth, you don't even need to hand hold it. Highly Durable - Heavy duty plastic construction and 100% rust proof. Immediate benefits - It will open the airways into your lungs that have been partially obstructed over the years, due to natural aging, pollution, poor physical condition, and smoking (if applic able). Long term benefits - Will target and develop the respiratory muscles ( the diaphragm and intercostals) to help you inhale more volume of air/oxygen into your lungs and to exhale more carbon dioxide out. Size: 10*5.5*3.5cm Shipping Color: As shown Quantity shipped: 1