Used to test the airtightness of capsules, the tester is made of stainless steel, to ensure its durability.

Cap the capsule on the neck of the bottle (model), immerse the cap in the water tank, then increase the internal pressure and observe if there are air bubbles coming out, so as to test the tightness in the air of the capsules.
It is generally used in breweries, beverage manufacturing plants, and corks.