1. Twoway watertight valve When the watertight valve is on the water, it can automatically close after being immersed in water. Fully dry antiwave head: Automatic water stop system, water stop is r, breathing is smoother, when the wave hits, it can effectively prevent water from entering the airway. 2. Silicone strap Good elasticity, durable, good workmanship, y and material. The swimming mask is made of soft, foodgrade liquid silicone, which is environmentally friendly and y. The easily adjustable mask buckles and flexible face skirt are perfectly designed to fit virtually any face shape and head size. 3. Environmentally friendly silica gel Nontoxic, tasteless, soft and comfortable; PC frame: no deformation, stronger and lighter; Antislip buckle: Professional antislip concaveconvex design, easy to adjust, antislip and antifall. 4. Safe tempered glass lens The diving mask has a nose cover, which is perfect for users who do not know how to stop breathing through the nose while swimming. Adjustment button: Highprecision adjustment of the lens strap to prevent falling off.