Professional Diving Mask Anti-fog Scuba Diving Snorkeling Silicone Mask Diving Equipment Adult Snorkeling Set Lens Material: High transparent glass lens; Frame: PC piano paint treatment processMirror crony: food grade silicone High transmittance tempered glass, clear vision. 700 Celsius steel processing, 3-5 times higher in anti-bending and impact strength than the same thickness of ordinary glass, not easy to cause serious harm to humans; good thermal stability, can withstand 300 Celsius temperature change German import silica gel, well-crafted, 100% fit facial, no worrying about water seepage, sea water resistant, prevent allergy Adjustable headband and ratcheting mask strap buckles: adjustable headband suitable for different head shape, easy to wear and comfortable. Perfect for snorkeling and recreational swimming for kids or adults with smaller, narrower faces