Ivation Snorkel Mask Set - Diving Gear - Single Lens Frameless Diving Mask & Snorkel w/Dry Top, Lower Purge Valve, Perfect for Diving, Snorkeling, Swimming Single-Lens Design Provides Wide Field of View for Underwater Exploration Tempered Glass Lenses Resist Scratching & Withstand Deep-Water Pressures Premium Snorkel Features Flexible Silicone Mouthpiece for Comfort & Durability Full Dry Top Prevents Salt Water from Entering Snorkel  Even When Submerged Lower Purge (Blow) Valve Enables Quick Expelling of Any Water from Inside Tube