This vacuum plug allows you to test your watertight enclosure for proper seal without getting wet! Here’s how it works: the barbed end is connected to a handheld vacuum pump and vacuum gauge and then you insert the other end into the vent on the enclosure. By pumping the vacuum pump, you’ll remove air from the enclosure, which simulates the same external pressure that the enclosure would experience a few meters under the water. The vacuum gauge let’s you monitor for leaks, which would cause vacuum pressure to decrease. Once you’re done, you simply pull the vacuum plug out and reinstall the normal vent plug to seal it back up.
It’s really important to check your test setup (the vacuum pump, hose, and this vacuum plug) for leaks before you test. Otherwise, if there’s a leak you won’t know if it’s in the test setup or in the enclosure. To help with that, it comes with a rubber stopper to plug the end of the vacuum plug to check the test setup alone.
The vacuum plug is made of 24 carat gold. Just kidding, of course – it’s actually made of anodized aluminum in a bright color to remind you to remove it and install the normal vent plug before going in the water.