The flutter is a small, lightweight mucus clearance device that requires no power and can be used anywhere and at anytime. Using the flutter can help to: Loosen trapped mucus & keep the airways open The flutter is suitable for the sufferers of: Chronic Bronchitis, Bronchiectasis, Emphysema, Asthma, Cystic Fibrosis. The flutter works by the user exhaling into the device which causes a ball bearing inside the casing to vibrate. Vibrations then travel back into the lungs which loosen the mucus in the airways. This triggers gentle coughing removing the mucus. Sessions normally last between 5 and 15 minutes.