Presidium gem tester.. don't know much about it, they don't make

Presidium Electronic Gem Gemstone Diamond Tester PGT by Presidium

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IMPORTANT TO NOTE: This product needs to be calibrated prior to use. If you experience issues with calibration, please reach out to the seller for

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Presidium GEM Indicator PGI Colored Gemstone Diamond Tester NEW

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Presidium GEM Indicator PGI Colored Gemstone Diamond Tester NEW