This is the ScubaPro Spectra Dry Snorkel for Scuba Diving and SnorkelingFeatures: Large-bore upper tube with dry top is designed for dry and easy breathing. Corrugated silicone lower tube allows the mouthpiece to hang out of the way when breathing off a regulator. Purge valve, positioned at the lowest point, takes care of any water that might enter the airway. Regulator-style mouthpiece offers good bite tabs for a comfortable fit, ideal for extended snorkeling adventures. Quick-connect clip makes it easy to attach or remove snorkel from mask strap. Designed to be the perfect companion to SCUBAPRO&';s Spectra masks, the restyled SPECTRA DRY is nothing if not the ideal snorkel. Its large-bore upper tube allows plenty of airflow, and its dry top design actually seals the tube when the snorkel is submerged so no clearing is needed upon resurfacing. An efficient purge valve expels any water that might make its way into the airway, preventing that annoying gurgling sensation you get when breathing off a "wet" snorkel. The lower corrugated tube is flexible so when you switch to your regulator the snorkel mouthpiece hangs out of the way. "