This item is a Check Valve that is used to keep water from entering an Ozonator while allowing the Ozone Gas to be sucked form the Ozonator.

The way the system works is the hose this valve is inline with is plumbed to a Jet ,Nebulizer or a Mazzie on the Air/Suction side. When the pump that runs through that Jet ,Nebulizer or a Mazzie is powered up there is a suction created on that line. When the suction is created it draws the Ozone Gas out of the Ozonator while sucking this Check Valve open. The Purpose of this Check Valve is to allow the Ozone Gas to be sucked out while not allowing water to enter the Ozonator. Keep in mind this Valve is only working to keep water out when the pump that is not running through this system. Therefore to test the Check Valve you would stop the pump and see if water comes out of the check valve or if there is Water in the Ozonator the check valve is bad. Note: This part being bad will cause a breaker trip if the GFCI System is wired correctly but can also cause voltage in the water if the GFCI is not wired correctly..