Latesd Advanced Breathing SystemThe completely independent intake tube and exhaust tube completely separate the fresh air from the exhaust gas, and the exhaust gas and oxygen will not mix, so as to prevent children from getting dizzy due to inhaling the exhaust gas. Compared with ordinary diving masks, this latest system allows children to experience snorkeling for a longer time, provides children with a safer and smoother breathing experience. Dry Top Breathing SystemThere is a floating ball on the top of the air intake tube. When the top of the tube is submerged in water, the floating ball will float up and block the air inlet tightly, preventing children from choking water due to water entering the breathing system. Combined with a tight waterproof structure, the floating ball design makes the Anti-Leak function of this snorkel mask very reliable. 180 Anti-Fog Clear ViewThis snorkel mask is equipped with transparent flat lenses to eliminate all dizziness caused by distortion of the field of view. The "mirror optical polishing" process greatly improves the clarity of the mirror, allowing children to appreciate the 180 underwater world more clearly. The snorkel mask has a physical anti-fog system, the product's gas separation structure separates water vapor and prevents fogging. Safe Material and Ergonomic DesignThe wearing part of this product is made of Skin-friendly food-grade silicone and high-quality textile elastic band, which is non-toxic and environmentally friendly. The ergonomic design allows kids of various face shape to wear it comfortably. The scope of application of this product is that the distance from the child's chin to the bridge of the nose is 3.35 to 3.94 inches (10cm). Please measure the data before purchasing. Notice and After-Sales GuaranteeFor safety reasons, please do not let children go snorkeling alone. We do not recommend that you engage in vigorous exercise, please rest regularly to keep you strength enough. Try this product before long snorkeling to make sure it is suitable for you.