Glass lens Anti-Fog Coating Tempered-Glass for Deeper Safety Adventure swim mask chooses the ultra-clear thickened tempered glass with a safety film to withstand deep water pressure for all types of diving or swimming. Scratching resist lens provides the clearer view under water.thiskids diving mask is with thick tempered glass lens, but please Don't toss them down on the tile floor, don't jump into water with the mask, don't scratch the glass with sharp objects. 180Panoramic View and Anti-fog Anti-UV Advanced lens shape design and thickened tempered glass with latest anti-fog treatment means you'll have a crystal-clear underwater experience without blurring or distortion. UV resistance can better protect your face from sun rays. One piece glass design enables better and wider vision under water. Easy Head strap Adjustment Fits Most Kids water mask fit a range of 5-15 years old children' faces. The straps of scuba diving mask can be adjusted by easily pressing masks' button buckle and the buckle will hold the strap securely in place without creeping down in the water. Tips to avoid the leakage: Tighten the mask and you can feel that the silicone skirt is fully absorbed on your face. (Adjusting the straps requires some patience) Soft Silicone Prevent Leaking? No! comfort seal skirt and strap adopt soft silicone, which molds to the shape of your face for comfortable fit and watertight seal. No more leak or discomfort. Soft liquid silicone face skirt comfortably fits a wide variety of boys and girls, reduces face water pressure, seals on kids' face well without worrying about water leakage when scuba diving snorkeling or swimming. Waterproof Soft Nose Cover swimming goggles is with soft silicone nose cover, which is needed to compensate for increasing pressure as kids swimming, snorkeling or diving. Also, it's helpful for kids who do not know how to stop breathing by nose underwater. Perfect for snorkeling and recreational swimming. Customers are our top priority, and we will happily replace any defected products. It is designed with wonderful safety so kids can focus on their snorkeling