Product purpose: Dive regulator valve and quick-connect plug designed for use with dive communication devices and as a practical tool for regulator maintenance and control. Material and durability: Made from high-quality brass for corrosion resistance, mechanical strength, and long service life in marine environments. Compatibility: Designed for the second-stage medium-pressure 16/9 adapter (open/close function). Fits systems that use a 16/9 medium-pressure interface. Key function: Acts as an open/close valve on the medium-pressure line to control air flow quickly and reliably. Useful for temporarily stopping or allowing flow without changing regulator settings. Connector behavior: The plug does not have a self-locking mechanism. It is intended for fast manual opening and stopping rather than a permanently locked connection. Ease of use: Simple, straightforward operation for divers and technicians; can be installed and operated without special tools or complex procedures. Performance benefits: Fast control of medium-pressure air flow for rapid response during service, testing, or in-field adjustments. Robust brass construction reduces wear and maintains sealing performance over repeated use. Clear mechanical behavior (no auto-lock) reduces the risk of unexpected locking or sticking in emergency or rapid-change situations. Use scenarios: 1) Pre-dive equipment checks: Install the valve on the medium-pressure 16/9 line to quickly isolate or restore flow during troubleshooting and functional checks of second-stage regulators or communication units. 2) Dive communication setup: Integrate the valve when connecting a dive communication device to allow fast manual shutoff or reconnection of the medium-pressure supply while preparing or testing the system on the surface. 3) Field maintenance and training: Use as a practical tool during instructor-led demonstrations or on-boat adjustments where a durable, easy-to-operate open/close valve is needed without a self-locking connector. What to expect: A durable brass valve compatible with second-stage medium-pressure 16/9 adapters. Manual plug operation for fast open/stop control; no automatic locking feature. Simple installation and operation suitable for divers, technicians, and instructors. Note: The product provides manual flow control for medium-pressure 16/9 systems and is not equipped with a self-locking plug. Ensure compatibility with your regulator or communication device before use.