Monitor humidity in sealed containers without opening them, protecting the inside from contamination. These plugs are often used on plastic bags, storage containers, and electrical housings. Consisting of a mounting nut and two gaskets for a tight seal, these plugs install through a hole in a flexible barrier. Remove one gasket and reverse the nut to install plugs in a rigid container. Watch the indicator disc through the nut’s viewing window—it will change color as humidity rises and falls. Made of anodized aluminum, these plugs resist corrosion and are lightweight. They meet military and SAE standards for humidity indicators.

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