MASK: Patented purge design. | Patented channeled skirt design directs bubbles away from view. | Ideal for medium to large faces. * Crystal, liquid silicone injected skirt and strap. | Double skirt edge comfort seal. | Low volume. | Swivel and adjustable buckles. | Tempered glasses. * SNORKEL: Built-in whistle housing. | Quick slip-in snorkel keeper. * Pre-curved flexible silicone corrugated low section. | Pre-curved silicone mouthpiece, prevents jaw fatigue. * Silicone purge valve for easy draining.