OMER Zoom Pro Soft Silicone Snorkel for Freediving and Spearfishing OMER Zoom Pro Soft Silicone Snorkel for Freediving and Spearfishing Ergonomically designed mouthpiece and airtube, Anallergic silicone 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 Internal diameter of the tube is 20mm, a specific dimension to optimize the air flow rate, Rigid enough not to vibrate during the ascent House Of Scuba Is An Authorized OMER Dealer!