Drytech also manufactures a range of humidity indicator plugs, which conform to MIL-I-26860. The Illustration below depicts a standard 2100 Series aluminum indicator body. It may be fitted with a single 40% RH (relative humidity) indicating paper or be provided with a multi level RH indicator. These plugs are externally mounted, color change humidity indicators for determining relative humidity within rigid containers and equipment, and also for use in flexible moisture vapor-proof envelopes or bags.