This is the XS Scuba 3-D Flex Dry Snorkel Features: The original dry snorkel! Nothing else compares! Unique floating valve system closes on contact with water Dry top opens automatically upon surfacing to eliminate vacuum effect Adjustable mouthpiece with swivel ball joint Smooth bore corrugated silicone tube allows mouthpiece to drop out of way when scuba diving Improved quick-release snorkel keeper for easy removal from masks The 3D Flex Dry Snorkel is the original dry snorkel. The unique floating valve system that closes on contact with water is the heart of this dry snorkel. When you see something on the bottom you want to get a closer look at using a conventional snorkel once you submerge your snorkel tube floods with water. Not so with the 3D Dry Snorkel. The float prevents water from entering the snorkel tube keeping it dry for your return to the surface. "