This is the Cressi Cressi F-Dual Frameless Single-Lens Dive Mask Features: The F-Dual is a single-lens mask featuring 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 for the ultimate in simplicity. The silicone facial is assembled directly on the glass without the need for a frame. This system guarantees good visibility in all directions. The low internal volume allows for effortless clearing and the quick-adjust strap buckles are molded directly into the skirt for a flexible fit and reduced 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 F-Dual is designed in Italy by Cressi and made in Taiwan. Cressi has been an Italian brand pioneer in scuba diving, snorkeling, and swimming equipment since 1946. The F-Dual is a single-lens mask featuring 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 for the ultimate in simplicity.