The Guardian Seahorse Snorkel Mask has a single window design with tempered glass lens for maximum clarity and scratch resistance. The quick-disconnect buckle system makes on and off easier than ever.• Single lens for a wide field of view• Tempered lens for ultimate strength• Quick-disconnect buckle for easy on and off• Soft PVC facial skirt for comfort Quick-disconnect buckle system for easier on & off Soft PVC facial skirt for comfort | Guardian Scuba Guardian Youth Seahorse Snorkeling Mask