Product Design The Supernova Dry snorkel features a floating mechanism that closes instantly to prevent water from entering the snorkel whether accidentally or purposely submerged Unique splash guard at the top reduces the entrance of water during use on the surface F-Dual single-lens mask features a unique assembly of lens and skirt without a frame to allow a wide field of view Mask bonds a high-grade silicone double-feathered edge skirt directly to a single tempered glass lens Performance Wide split strap design provides comfort and even-tension on the skirt for a proper seal Quick-adjust strap buckles are molded directly into the skirt for a flexible fit and reduced drag Top valve seals the tube as you dive, almost totally blocking the entrance of water when the snorkel is submerged A special water collection well, with a large elliptic valve, allows quick and easy expulsion of water