Size: L/XL or S/M. • Dry technology snorkeling • GoPro camera holder (GoPro camera not included) • Double ventilation ducts • Drain valve • Elastic nylon straps • Shatterproof polycarbonate glass with 180° wide viewfinder • Inhalation - natural air inhaled by the nose. Exhalation - natural breathing through the nose PRODUCT INFORMATION • Breathing tube - removable, easy to carry • Wide vision - polycarbonate surface, wide vision 3D arc • Dual anti-fog airflow channel - fan effect • Large drain valve - raise your head to drain • Waterproof - stop-water system, smooth breathing • Easy to put on and take off - adjustable elastic strap • Comfortable to wear - liquid silicone lip, meet the requirements of environmental protection • 180-degree super wide vision, no blind spots, durable • Lift up to drain the water through the valve at the bottom of the diving mask TECHNICAL DETAILS • 180° Arc Wide Field of View - An arc-shaped polycarbonate surface that gives wider vision without blind spots so snorkelers can fully enjoy the underwater world. • Physical anti-fog principle - fan design, effective physical anti-fog, no breathing tube, relieve discomfort, more hygienic. • Achieve a physical anti-fog effect by reversing the direction of exhalation and inhalation. Inhale - inhale naturally. Exhale - exhale naturally. • Completely dry breathing tube - stops water quickly, large filter and fine filter are perfect for this. HOW TO CHOOSE A MASK SIZE First, measure the length from the eyes to the chin. If the length is less than 13.5cm, please choose size S/M (suitable for teenagers and adult women). If the length is equal to or greater than 13.5 cm, please choose L / XL (suitable for adult men).