DUOYI has more than ten years history of electrical and electronic tester manufacture, specializing in profession test equipments, including insulation resistance tester, earth tester, socket tester, automotive tester, transistor tester, gas tester and multimeters, to provide an all around measuring solution ranged from industry to components. Our insulation tester and earth resistance meter maintain market share 20%-25% in China market, while automotive testers sharing market up to 90%. We are proved an active part and place in China electrical instrument industry, with well accepted and solid quality.