Frameless Mask - Ideal for medium faces - face Seal Size W4 3/4 * H3 1/2. 170 degree wide view. Tempered glass. Crystal, liquid silicone injected skirt and strap. Double edge comfort seal. Ultra lightweight. Extremely low volume. Quick Release Swivel Buckle - allowing easy removal of strap and inclinations in various angles. Made in Thailand. Snorkel: Built-in whistle housing; Quick slip-in snorkel keeper; Pre-curved flexible silicone corrugated low section; Easy purge valve keeps stocking water out -- When feel water stocking in the bottom of the snorkel, simply squeeze the easy purge valve and spit out, which drains water from the bottom of purge that keeps the airway clear; Pre-curved silicone mouthpiece; prevents jaw fatigue; Silicone purge valve for easy draining.