ForShine Snorkel Mask,Snorkeling Mask with Detachable Camera Mount,180 Degree Panoramic View Anti-Leak Anti-Fog Snorkel Gear for Adults & KidsPreparation:Make sure there is no sand on the mask or tube, if there has sand, use water to clear the breathing tube or mask, once the mask is clean then it is ready for usechecking the seal:Pull the straps o..