Aqua Lung Impulse 3 2-Valve Flex Snorkel The reservoir located below the mouthpiece keeps breathing path clear of excess water. In the rare event that you need to clear the Impulse 3 Snorkel, almost no breath is needed. All it takes is an easy puff. The unique design of the Impulse 3 snorkel, with its large bore, delivers extremely low breathing resistance while the body of the snorkel creates little drag. Patented Comfo-bite mouthpieces, which eliminate jaw fatigue, are replaceable and an optional, smaller size is available Removable keeper allows easy attachment or removal of the mask