The Zoom snorkel series has been developed, by our technicians, specifically for spearfishing and free diving. The shapes of the an allergic silicone mouthpiece and the air tube have been ergonomically designed to follow the profile of the spear fisherman"s face, to greatly reduce its visibility during the dives. The internal diameter of the tube is 20mm, a specific dimension to optimize the air flow rate. The strap holder is easy to use and reduced to minimal dimensions. The tube of the Zoom Pro is manufactured in TPU, an extremely flexible plastic material with a high mechanical strength used mainly for articles subjected to wear and for all heavy-duty engineering components. The tube will undergo no swelling in water and won"t yellow under the action of UV light. The snorkel has a high rebound elasticity and "snappiness", allowing the diver to fold it when it is not needed, and to take it out whenever the use of a snorkel becomes a necessity. Still, it is rigid enough not to vibrate during the ascent. The Zoom Transparent is part of the "Inshore hunting line by Marco Bardi". The silicone mouthpiece, the rigid PVC tube and the strap holder are all manufactured in crystal clear plastic materials with the specific intention of making it completely invisible when submerged. This is based on the simple but effective idea that the perfect camouflage is in fact transparency. The Zoom snorkel is the same as the Zoom Pro but it features a non-foldable rigid PVC tube.