Aqualung SideDraft Flex Snorkel The unique air vent virtually eliminates splash water entry and provides an opening greater than the tube bore for excellent clearing Large reservoir at the base keeps residual water out of the breathing path Patented Comfobite mouthpieces, which does not require the user to clench their teeth, eliminate jaw fatigue An optional, smaller size Comfobite is available Comfobite mouthpieces are replaceable