Sinus Saver nose plugs are a new device invented by a California surfer in his quest to find relief from recurrent sinus infections and chronic sinusitis caused by water entering his nasal passages and sinus cavities while surfing. Conventional nose clips, which squeeze onto the outside of the nose, were not helpful, because they came off while duck - diving powerful waves. Plus, they don't look cool. After an exhaustive and unsuccessful search for a more effective option, he created the Sinus Saver Ultimate Water Sports Nose Plugs. The Sinus Saver plugs fit snugly into the nasal cavity effectively blocking water from entering the nasal passages. The nose plug consists of two flexible cups connected by a narrow bridging band. It is made of high-grade medical grade silicone, which will not dissolve, shrink, or break during normal use. The cups at each end are inserted into the nose, leaving only the bridging band exposed. This extremely low profile makes the nose plug barely noticeable when worn and significantly reduces the chances of it coming off when hit by water. The cups are soft, pliable, odourless and comfortable to wear. Their softness and pliability minimises potential injury in case of collision with surfboards, kayaks, and wake boards. The Sinus Saver Ultimate Water Sports Nose Plugs were invented specifically for use in active or extreme water sports and swimming. PLEASE PAY ATTENTION TO SIZING DETAILS AND SIZE DOWN WHEN IN DOUBT. Our large size is very large, so be certain it is right for you before ordering. To determine size, use a group of Q-Tips to measure the size (diameter) of your nostril. If you can fit 8 or more Q-Tips tips into the opening of your nostril, we suggest the large size. For 7, we suggest the medium. For 6 and under, small or extra small. Please feel free to contact us with any sizing questions or problems.