CRYSTAL Silicone is an exclusive CRESSI material that revolutionizes mask skirt clarity. It offers incredibly clear vision and features long-lasting advanced technology components within the pure silicone skirt which prevents premature discoloration, reduces fogging, and guarantees many years of CRYSTAL clear viewing. CRESSI CRYSTAL silicone : Another Exclusive Industry First Not only has this new High Seal silicone been chosen, with its exceptional softness and comfort, but the entire design of the skirt has followed new rules which allow a point of contact between the mask and the face that has a very open angle. The mask rests on the face with unprecedented comfort and does not leave any marks on the skin, even after extended use. Naturally, to obtain such a result the entire structure of the skirt is differentiated, with internal ribs that stiffen the parts of the mask that are most stressed. The raked lenses, with their inverted drop shape (Cressi patent), are quite small and are brought as close to the pupils as possible, so that the already extraordinary visibility of the Matrix is increased by 25%. The headband uses the exclusive patented Cressi system of double injection of an elastomer on a rigid element and allows the buckles of the strap to be mounted not on the skirt structure, as done by our competitors, but on an indestructible elastic element that tilts on a vertical plane and can be completely bent sideways on a 180掳 curve. The thickness of the headband has been reduced to such an extent as to make it practically invisible when the mask is being worn. Big Eyes Evolution has been created to take prescription lenses: a small screwdriver and a few seconds are all it takes to replace the standard lenses with prescription lenses.