NO HURT NO PAIN. ULTRA FY - Exclusive Ergonomic Design. US DESIGN PATENT. And Quality Soft Silicone. Super Soft Super fortable. DOUBLE WATERPROOF - Unique Designed Structure,2-layer Waterproof Fs. Great Help to Enjoy Swimming Showering and Water Ges. Life-chanr. Safe in All Aspects - 1) One-piece design, of small objects falling into the ear canal. 2) Resistant to 392°F high temperature,it won't be melted by the body's heat,and won't cause falling into deeper ear canal or stiing to hair. Sound HoleUsers can hear warning sounds from the environment or swim . MULTI-SIZE - Specific sizes for infants,toddlers,children,teens,women,men,including small medium and lar ear users. Much better than One-size-fit-all. Refer to Size Chart for more details. HOW TO CHOOSE THE CORRECT SIZE - Mixed-Size for new users,also for users having different size of left and right ear canal..