Cressi F1, Scuba Diving Snorkeling Frameless Mask - Cressi: Quality Since 1946 Cressi is a Real diving, snorkeling and swimming Italian brand, since 1946. Clear Wide view by a single lens made with high quality Tempered Glass, anti-fog. The F1 mask is made with 100% silicone, a better and longer lasting material than plastic PVC. The best for a Perfect and Confortable Seal. Micrometric Easy Adjustable Buckles for better confort. Designed and created using Innovative and Patented Manufacturing Technology.