Zoggs Predator Flex Reactor Swimming Goggles Silicone EXTREMELY COMFORTABLE: Super soft medical grade silicone is unique to our goggles. Allows for an extremely comfortable and super soft fit around the eyes for a more pleasing swim and won't cause headaches like traditional swim goggles. REACTOR PHOTOCHROMATIC LENSES: Provide the perfect lens tint for ALL swimming conditions. Lenses automatically adjust from light to dark tint and back quickly to protect eyes from the sun and fatigue. PATENTED NOSEBRIDGE: Our Unique, Exclusive, one of kind nose bridge is engineered to retain it's shape and will not spread when the head straps are tightened. This allows for room around your nose bridge despite how much the gaskets are stretched outward. BEST ANTI FOG TREATMENT IN THE INDUSTRY: Instead of a film like other swim companies, our anti fog is part of the material of the lenses and is made as part of the lenses in the manufacturing process. DOUBLE HEADSTRAP: Split Head strap wraps around both the top and lower part of the back of the head, offering more security so that you don't lose your goggles when swimming.