We’re so confident in the durability of the Atomic Aquatics SubFrame Mask that it carries a limited-lifetime warranty against frame breakage. Its strength comes from its internal frame (subframe) molded directly beneath the surface of the silicone rubber skirt. The subframe provides incredible strength and rigidity as well as eliminates the bulky external plastic frame found in other masks. A stainless-steel retainer locks the lenses in place and provides added strength to the nose bridge area of the mask. A wide field of view and great fit completes the combination of function, style and durability in the most indestructible two-window mask ever.