Two-way watertight valve and fully dry top - Two-way watertight valve closes automatically when submerged, helping to keep water out. - Fully dry anti-splash top with an automatic water-stop system reduces water entry during waves, supporting safer breathing and a calmer swimming experience. Silicone strap, comfort, and fit - Made with soft, food-grade liquid silicone that is elastic, durable, and body-friendly. - Environmentally friendly and safe material. - Very easy to adjust with flexible facial skirt and adjustable mask buckles to fit most face shapes and head sizes. Safe lens design and nose breathing support - Tempered glass lens for clear vision and durability. - Nose cover designed for users who breathe through the nose while swimming. - High-precision lens strap adjustment knob helps secure the lens and prevent slipping or loss. Environmentally friendly materials and robust construction - Environmentally friendly silicone gel that is non-toxic and tasteless, soft and comfortable against the skin. - PC frame provides strength without deformation, delivering a lighter, more durable mask. - Anti-slip buckle with a professional concave-convex design for easy adjustment, improved grip, and drop resistance. 2-3 practical use scenarios - Pool lap swimming and training: the two-way valve and dry top help minimize water intrusion, supporting steady breathing during long sets. - Open water swimming and snorkeling: reliable sealing and secure fit in waves and splashes, reducing distractions and maintaining vision. - Recreational water sports: the combination of a flexible face skirt, adjustable buckles, and secure lens strap offers a comfortable, reliable fit for varied activities and movements. This product combines functional water sealing, comfortable materials, and a secure, adjustable design to support safer, more comfortable swimming across different environments.