Cressi Calibro + Corsica Snorkeling Set - Green, UniFeatures Tempered Glass High quality' Lenses High Quality Silicone Skirt The visibility provided by the single lens and the unusual shape of the frame extends in all directions. Snorkel that has been designed specifically for deep fishing and free diving The tube of the Corsica uses a new concept of special polymers that have excellent shape memory Product Description Cressi's next generation diving masks are all equipped with the IDF INTEGRATED DUAL