Air Venturi Quick-disconnect Test Plug or dust plug
Provides a handy way to plug the female quick-disconnect on your tanks fill hose to check the pressure inside of tanks that do not have an internal pressure gauge by blocking the airflow to allow the use of an in-line gauge.
Insert the test plug in the standard quick disconnect coupling at the end of the pump hose to test your pump. The plug blocks airflow, providing a contained circuit to test.
Can also be used to protect the quick disconnect fitting on your pump OR tank from dust and external debris