EXCLUSIVE PRESSURE RELEASE PLUG
The body and lid are uniquely designed with a "no clip" closure arrangement. Our testing has shown that this arrangement allows the water to exert an even pressure on the O-ring, thus increasing the reliability of the watertight seal. To open the housing, the pressure release plug must be first unscrewed and then pulled all the way out. This provides a channel for the air to pass though and eliminate the pressure differential between the inside of the housing and the ambient air pressure.
The plug consists of an internal double O-ring seal on a stainless steel slide shaft. These internal O-rings form the watertight seal. There is also a large outer O-ring under the knob. This O-ring serves to prevent contamination [dirt or salt] of the slide shaft, and is not required for watertight integrity. If this O-ring should become detached, it can simply be pushed back in place.
Before diving, make sure the pressure release plug is pushed closed, and then screwed home, do not over tighten this plug (finger tighten only).
