Unique Respiratory System: We use K2 unidirectional (outer) circulation breathing separation, separates expiration from inspiration mechanically. Inspiration enters through the dual breathing tube. The carbon dioxide exhaled as well as residual oxygen not inhaled into the body that discharges from the outside of the mask respectively. Thus, prevent carbon dioxide from entering the body to cause life threatening and other accidents.
100% Anti Fog & 180 Degree Panoramic View: our diving mask underwater was tested tens of thousands by our team, It can be anti fog up to 15000 hours. Besides, optimized lens shape and refined lens allow 30% clearer distortionless visibility as well as wider visual field
360°Rotatable Breathing Tube: HJKB Snorkel Mask adopts two breathing tubes, 360°free rotation, supports backstroke, and can easily meet any posture under water. Two intake tubes are feeding fresh air circulation by the mouth and nose together and makes it easier than ever to breathe while you are snorkeling. The new dual-tube breathing mode avoids blockage of a single breathing tube and don't worry about leaks or choking water.
MEDICAL ORIGINAL MATERIAL AND SIZE: 3rd Snorkels Mask Made of High Quality PC and Medical Grade Silicone. Non-toxic and environmental, which can prevent skin allergic or other skin problems caused by original materials. The size is measured from the eyebrow to the bottom of your chin. If less than 5.1in(13cm) and please select size S/M, if more than 5.1in(13cm) and please select size L/XL. Generally, S/M is for women and teenagers, L/XL is for men. See the size.