【Anti fog design&Double Snorkel design】When inhaling, oxygen directly enters the Snorkel mask through the ventilation tube, and when exhaling, carbon dioxide is discharged from the exhaust port, which is not a channel with the inhalation port and does not produce fog. There is no sense of obstruction in breathing, and breathing is very smooth. 【Can install Action camera&180 ° ultra wide angle】 The Snorkel Mask adopts an ultra wide angle field of view design, with a 180 ° field of view allowing you to enjoy the beautiful scenery of the sea. There is a Action camera capture button and you can install the sports camera. (No camera included) 【Adjustable buckle strap】 It has a strap with good elasticity and adjustable looseness, which can be adjusted for comfort according to the shape of one’s face, making it easy to use. The facial contact area is made of soft silicone, which is non-toxic and will not cause discomfort after prolonged use. 【Excellent sealing and water immersion prevention】 The face and snorkel mask are tightly pressed together to prevent water immersion.In water, the floating ball blocks the air vent due to buoyancy, preventing water from entering. On the surface of the water, gravity causes the floating ball to fall, the air inlet opens, and the user can continue breathing. 【Mask size】 Distance from the most concave part above the nose bridge to the chin: S/M: 10-12cm L/XL:>12cm，Children over 9 years old and women are recommended to use S/M size. Men are recommended to use L/XL size.