The Cressi(R) Big Eyes Evolution Crystal Mask features a newly designed crystal skirt that is exceptionally comfortable and non-marking, even during prolonged use. This revolutionary design has three interior silicone bridges that enhances the fit and feel while underwater. Visibility is increased by 25%, thanks to the inverted drop lens shape that is as close to the pupils as possible. FEATURES: High seal materials are soft and comfortable Downward angled lenses are close to pupils for increased 25% vision New crystal skirt design allows it to rest of face with no marking Internal ribs stiffen the parts of the mask that are most stressed Reduced headband thickness makes it practically invisible when worn Designed to take prescription lenses 100% silicone skirt with tempered glass lenses Designed and created using innovative and patented manufacturing technology Manufacturer's 2-year warranty For additional information relating to the Manufacturer's Warranty, please contact 201-594-1450.