w wstoo snorkel mask with latest dry top breathing system,fold 180 degree panoramic view full face snorkel mask anti-fog anti-leak with camera mount,snorkeling gear for adults w wstoo <b>preparation:</b><br>make sure there is no sand on the mask or tube,if there has sand,using water to clear the breathing tube or mask,once the mask is clean then it ready for use.<b><br><br>checking the seal:</b><br>pull the straps of the mask over your head and check the fit of the mask on your face,breath normally to check for any leaks,if you feel slight pressure change when you breath,then you have a good seal,if not,please kindly adjust the mask wire size.<b><br><br>using:</b><br>once in the water,swim on the surface and breathe calmly through your mouth or nose,if you feel light headed remove the mask immediately,keeping your chin slightly up will create the best breathing experience,if you feel any obstruction to your breathing,it may be due to the snorkel being covered in water temporarily,the dry top snorkel design will prevent water from entering through the top of the snorkel,if water leaks into your mask,simply lift your head out of the water and it will drain out of the chin valve,no need emove your mask to clear it of water.<b><br><br>proper use:</b><br>full face snorkel masks are designed for leisure surface snorkeling. serious freediving is not recommended. strenuous swimming while wearing any type of snorkel, including full face designs, is not recommended. be sure to take regular breaks while snorkeling. also follow the buddy rule: never snorkel alone.<b><br><br>if you are not satisfied with our products,we will provide you with a 100% refund.</b><b><br><br>if any quality problems are found within 90 days after you buy this product,we will offer replacement for a new product free of charge.