Correct use : The Full Face Snorkel Mask is designed for recreational snorkeling. It is for surface snorkeling only and is not intended to replace any professional snorkeling kit or dive equipment. When snorkeling, be sure to take regular breaks and follow the buddy rule: never snorkel alone. Before you go snorkeling, try it out in the pool to make sure it's completely sealed and fits your face. How wear ? Lift your hair back to avoid hair entering the inside of the breathing tube mask and causing a gap between the mask and the face connection; put your chin into the inside bottom of the mask and press the bottom connection with your hand to check if there is a gap. After checking there is no problem it can be used normally. If you find that the mask does not fit your face well enough, you can adjust the tightness of the mask to your face by adjusting the expansion band. Note: Please put the mask into the mesh bag after use to prevent the mask from being scratched on the beach and affecting the subsequent use. How use ? Before use, you can wipe the inside of the mask with the anti-fog wipes included in your snorkeling bag, which will improve the mask's anti-fog ability. For surface snorkeling only (less than 3 meters/10 feet). Do not wear this product for scuba diving, deep diving, or free diving. Hair or whiskers create micro spaces that allow water to seep in. package included : 1 x Snorkel Mask 2 x Breathing Tube 1 x Mesh Bag 1 x User Manual