<p>The Atomic Aquatics SubFrame Mask is so durable, it carries a Lifetime warranty against frame breakage. The strength comes from the internal frame (subframe) molded directly beneath the surface of the silicone rubber skirt (patent pending). This subframe provides incredible strength and rigidity as well as eliminating the bulky external plastic frame 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. (US Patent #7,181,778) </p> <ul> <li>Unmatched durability and resistance to breakage </li> <li>Optical quality, distortion-free UltraClear lenses </li> <li>Hydrodynamic styling with no exposed external frame </li> <li>Wide vision and low volume </li> <li>Great fit </li> <li>Squeeze to adjust buckles </li> <li>Clear or Black silicone rubber with co-molded color accents </li> </ul> <p>UltraClear is a new and exciting optical quality glass with exceptional clarity and high light transmission, with no color distortion. The exceptionally high light transmittance and lack of distortion in the UltraClear lens maximizes the light available for improved visual acuity, especially underwater in low light conditions. </p> <p>What makes UltraClear special? Did you ever notice that normal dive mask lenses have a green tint to the glass? To see this tint, put your existing mask up to a piece of white paper and see for yourself. The green tint you see is the result of iron impurities left over in lower quality float or window type glass. That green tint distorts true colors and blocks out some of the light that reaches the eye. </p>