Thanks to the collaboration with a leading Italian Orthodontia Study, Mares created the best hypoallergenic silicone mouthpiece characterized by unparalleled easy breathing and especially well-suited for prolonged use. Diameters and lengths are optimized, avoiding any air turbulence and making clearing easier. Anatomic and hydrodynamic shape: The D-section shaped tube eliminates discomfort in the area that touches the temple. In the dual version, the tube is made in two materials with two different softness levels to decrease vibrations and noise when moving about during the dive. Increasing comfort without causing interruptions in air flow. A classic "J"-style snorkel that has been tried and true, the simple design makes this snorkel almost bullet proof and reliable compared too many of the newer high-tech snorkels on the market. No fancy valves on top or bottom, if you can blast clear a snorkel than this is what you want. Snorkel comes with a low profile hydrodynamic snorkel keeper, and is available in multiple colors.