Our adults full face snorkel mask has a dual float ball design that prevents water from entering the mask by using gravity and buoyancy. It keeps the breathing tube dry to ensure diver safety. Compare with other snorkel masks, it is designed for inhaling only, and the amount of oxygen that can be breathed has doubled. Our snorkel mask has four breathing Tablets in the air chamber for enhanced breathing and 2 side exhale breath Tablets that eliminate carbon dioxide, reduce dizziness and prevent bubbles from obstructing your view. Our scuba mask has transparent flat lenses with a 180° panoramic view, providing clear underwater views without distortion, dizziness or discomfort. It features removable motion camera brackets for capturing and sharing your snorkeling experiences, and is suitable for all ages and skill levels. Our adults snorkeling gear has a high-quality silicone construction that fully wraps the mask to prevent leaks. The interior layer isolates inhaled air and reduces condensation on the mask surface, creating a professional-grade anti-fog and anti-leak design for an amazing snorkeling experience. Measure from the bridge of the nose to the bottom of the chin, and select the appropriate S/M size(less than 5.1inches) or L/XL size(more than 5.1inches).