About this itemBreath Diving Mask(L/XL): snorkel mask breathe naturally and comfortably through your nose and mouth. Flowtech has two chambers and 4 intake valves to allow air to circulate in and out freely. Using one-way valves and a separate breathing chamber ensures fresh air is always circulating through the mask. Making it easier than ever to breathe comfortably through your mouth or nose while you are snorkeling.Ultra-wide Uninterrupted Vision + Without Distortion Scenery: 180extra wide and uninterrupted visual field which means there is no frame that obscures your view so you can see more sea creatures than ever before. Flat lens show optimal reality and legible scenery. It unlike curved lens which makes everything seem to be farther away than normal and will not cause dizzy and headache when snorkeling.Top Dry System + Dual Anti-foggy Technology: Floating ball waterproof valve on the top is automatically locked to prevent salt water from entering your mouth or nose, so you will no worry about safety problem and focus more on snorkeling. Separate inhaling and exhaling channels (high volume air-flow structure allows 50% more than normal diving masks) effectively stops fogging in physics. Besides, anti-foggy coating on the lens enhances the anti-fog effect in chemical.Adjustable Comfort Fit+ Camera Mount Design: L/XL size snorkeling mask is designed for adults and youth, the elastic head bands better fit your head shape while the silicone skirt provides a soft, leak-resistant fit.(Not suitable for children under 14 years. To be used under the direct supervision of an adult) You can adjust the camera mount position to the right height and easily plug camera to capture your unforgettable underwater journey.Important Sizing Tips: Full face snorkel mask adult sizing is important to get right. Be sure to measure from the bridge of your nose (between your eyes) to the tip of your chin. Measure along the side of your nose, not over the top. Follow the sizing chart. If you are in between sizes, it's usually best to select the smaller size. For the best seal, you may need to tweak the placement of the mask on your face until you have the most comfortable fit. Be sure to test in a pool before your trip.