OBOSOE Snorkeling Mask, Anti-Fog Scuba Diving Mask for Adults, Kids ONE SIZE FITS ALL - This snorkeling set comes with very soft and fully adjustable head straps and a high-grade silicon face skirt which molds to fit virtually any face shape. The ribbed design provides extra support and ensures a water-tight seal (100% leak-proof). It is comfortable, and super easy to adjust and perfect size while you are wearing it. ANTI-FOG TEMPERED GLASS - Enjoy maximum under-water visibility and a wide field of view. Not only anti glare and UV, but also anti fragmentation, impact resistance. Advanced lens technology (using an inverted teardrop design) and tempered glass with tested anti-fog treatment mean you'll have a crystal clear underwater experience. PURGE VALVE & SPLASH GUARD - The advanced anti-splash system prevents water from entering the snorkel and the purge valve allows for easy clearing and draining of the snorkel. PROFESSIONAL GRADE MATERIALS - The mask and snorkel are manufactured using top grade materials. The silicon mask and mouth-piece provide maximum comfort and long-lasting performance. GUARANTEE - This snorkeling set for adults is backed up by a lifetime hassle-free guarantee. Our snorkel gear and scuba equipment is fully tested and we stand by every single product. If you have any issues, contact us for quick and easy help. Customers are our top priority and we will happily replace any defected products.