Slide isolator. Great for Rebreather Diving. Inline shut off for ADV, Solenoid, MAV buttons, etc.
Generally this shutoff is used for the purposes of isolating the Automatic Diluent Valve (ADV), Oxygen Solenoid, or manual add valves (MAV) on a rebreather. The benefits of being able to isolate these systems are many. In the event of a free flow divers can easily shut off and isolate gas addition systems and end their dive in a reduced but manageable state.
The isolation of an ADV is also beneficial during hypoxic trimix rebreather dives where the gas in a diluent cylinder may not be breathable as shallow depths where inadvertently adding it could result in the rebreather diver losing consciousness.