The Deep Blue Gear Maui mask offers extremely low volume in a contemporary design, resulting in increased peripheral vision and comfort. Durable buckle assemblies and stainless steel pins complement the heavy duty silicone mask strap. Just like the Spirit 2 mask, the Maui prescription dive mask has a steel buckle pin for durability and a swiveling buckle assembly for added comfort. The liquid-injected silicone mask skirt also offers a comfortable fit while getting a good seal with almost any size or shape of face. At Snorkel-Mart, we've made it easy to select the right prescription lenses. We carry pre-made optical lenses made with tempered glass that we match up as closely as possible to the values from your eyeglass prescription. We take into account both the Sphere and Cylinder values from your prescription and then do a calculation (we add half the value of the Cylinder to the Sphere and then round down to the nearest half) to find the closest possible optical correction needed. With prescription lens values ranging from diopter increments of +4.0 to -10.0, we have been able to accommodate thousands of snorkelers and divers alike with the prescription lenses that they need. For most casual snorkelers, the prescription lenses offered in the Maui mask work fantastic! Our prescription masks are in stock ready to ship either the same day or the next business day after an order has been placed!