The valve design incorporates a reservoir and purge valve along the outside wall of the mouthpiece. This aids in the expulsion of water and results in an easy breathing snorkel. The rubber tube is a fairly large bore and is perfectly legal for UWH. The mouthpiece and purge section are made from a softer rubber with a built-in pivot so the mouthpiece can easily be angled for maximum comfort. The snorkel attaches to the mask by a standard rubber snorkel keeper.