Automatically activates if internal helmet pressure becomes too great. Can also be manually adjusted to improve breathing when operating in the open circuit mode or it can act as a standalone feature to dump exhaled gas directly into the surrounding water.

Positive shut off valve is spring loaded. Internal pick up tube reduces chance of exposure and increases effectiveness in dewatering the helmet.

Two stage regulator that controls and routs the exhaled gas. Rapid removal and replacement is possible with clear access to all fasteners.