Suitable for snorkeling only, not for scuba diving The main obstacle to snorkeling is the difficulty of breathing underwater with the snorkel. It is true that breathing through the mouth is unnatural, and the mouthpiece of the snorkel is sometimes considered too intrusive, uncomfortable and unhygienic. This is a replacement/compatible Gopro product A full-face snorkeling mask that allows you to breathe as easily and naturally underwater as you would breathe through your nose and mouth on land. To ensure that water does not enter through the breathing tube, the mask is equipped with a mechanism that blocks the top of the breathing tube when submerged in water. Also, the top of the snorkel is highly visible to avoid any bumps on the surface. Mask, not suitable for freediving Wide Field of View----- 180 field of view and shatter-resistant polycarbonate window for added security. Breathe easily - full face mask for natural breathing through the nose and/or mouth. Anti-fogging-----The unique breathing ventilation concept prevents fogging. Watertight/Sealed - The dry top vent system prevents water from entering from the top of the vent. Drainage------A bleed valve at the bottom of the mask allows water to drain out when the head is raised. Easy to dress ----- Adjustable elasticized textile straps won't pull out your hair. Visibility - The top of the snorkel can be seen from 4 times farther than conventional snorkels. Swimming depth-----Reminder: mask, not suitable for free diving. Compatible with Gopro feature: Durable, with a camera mount for easy attachment to gopro cameras. Dual Airflow Channels - Separate inhalation and exhalation channels for anti-fog. The wide-edge double-sealed design is derived from imitating the human face and is made of liquid silicone that will not irritate the skin.