The F-Dual is a single-lens mask with a unique assembly of lens and skirt without a frame. The mask design bonds a high-grade silicone double-feathered edge skirt directly to a single tempered glass lens. The silicone facial is assembled directly on the glass with no need for a frame. This system ensures good visibility in all directions. The low internal volume allows for easy clearing and the quick-adjust strap buckles are molded directly into the skirt for a flexible fit and less drag. The F-Dual mask has a wide split strap design for comfort and to give even-tension on the skirt for a proper seal. The Supernova Dry has a unique Splash Guard at the top that reduces the entrance of water during use on the surface. The special valve on top 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.