The Pre Owned Yf-509 Digital Insulation Tester by Tenmars is a high-quality device designed for testing insulation resistance. With a test voltage range of 1000, this tester is reliable and accurate in detecting insulation quality. Made in Taiwan, this unit is a must-have for professionals in the field of electrical testing and inspection. The product comes individually, ensuring you have a dedicated tool for your testing needs. It powers on and goes through all the settings but I honestly don’t know how to use it and what to use it but It is in good condition and I am pretty certain it will be fine
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