Whale? 2016 Seal Silicone Skirt Strap Snorkel Scuba Dive Mask with myopia and hyperopia lens Diving Equipment The mask's double lens design provides a closer view for thrilling pool or ocean adventure. Treated for fog-resistance, the glass lenses offer unobstructed and crystal-clear vision for up-and-down, side-to-side, and complete peripheral sight. The tough panes are crafted of tempered glass to resist scratching, cracking, and inadvertent breakage if hit while exploring underwater environments. This resilient material and the close fit deliver peace of mind when diving into deep pressures. High quality silicone skirt and strap. Designed to fit a wide range of facial profile with comfort. Whale brand focus on diving mask for 17 years,professional in technology,superior in quality,friendly in customer service!