Greatever Classic Exploration Dry Snorkel with Splash Guard and Top Valve

BOTTOM PURGE VALVE1. Drip out extra water from tube automatically.2. Clear the snorkel easily with a good blow or liguid water. Ergonomic design easily attach to any regular snorkel/dive mask Food Grade Material Specification   Matierial Buckle：PC Drain valve: PC Tube:PVC Mouthpiece: Food grade liquid silicone Threaded tube: Food grade liquid silicone Size Tube: 38cm(15 inches)   FAQ 1.Can this be used for lap swimming in a pool? The most common use given is in the ocean ( snorkeling) If you would like to use it in a pool to aide in swimming you can do that as well. 2.Do i nead a head bracket to use it or just use my goggles to hold it?The strap of your goggles would slip into the snorkel keeper on the side of the snorkel and should stay up by itself when in the water. However, snorkels tend to work best with a mask (that covers the nose as well) than goggles that only cover the eyes. 3. What size is the purge valve gasket ?The size is averag