Shining Diving Mask Underwater Scuba Anti Fog Full Face Snorkeling Set With Skid Ring Snorkel 1. Longer breathing tube Experience deeper and more enjoyable swimming 2. One earplug, not worrying about getting in the water, getting rid of all the restraints 3. Waterproof design at the interface between the breathing tube and the mask. It is our responsibility to give you the safest protection. 4. Mask mouth design is more conducive to breathing, more beautiful, more cool How to choose the size? Firstly, Measure the length from the Eye to Chin. If the length less than 13.5 cm, Choose size S/M. (Suitable for The Junior and Adult Woman) If the length equal with or over 13.5 cm, Choose size L/XL(Suitable for Adult Men)