Flexible Silicone for Leak-Proof, Comfort Seal: Skirt and strap come in soft, supple silicone, which molds to the shape of your face for comfortable fit and watertight seal. No more leaks or discomfort.<br> Tempered-Glass Lens for Safety: Forget flimsy plastic lenses! This one is quality tempered glass, which resists scratching and shattering.<br> Convenient Buckle for Easy Adjustment: Simply pull the straps to desired fit and the buckle will hold the straps securely in place. Presto: customized comfort.<br> The Optimum Dive mask has a stylish modern design, with a cool black finish. Paired with the Optimum Dry Snorkel, you will truly look awesome while you are out there having fun. Relish and enjoy the adventure in style.<br> One-Piece Lens: A snorkel mask should help you see better, not obstruct part of your view. Now you can enjoy all the underwater scenery clearly.