WSTOO Full Face Snorkel Mask-Advanced Safety Breathing System Allows You to Breathe More Fresh Air While Snorkeling,180 Panoramic Anti-Fog Anti-Leak Foldable Snorkel Mask for Adult and Kids

Preparation: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.Checking the seal:Pull the straps of the mask over your head and check the...