General Description: HD921 is 3 1/2 digital clamp meter with steady performance\safety and reliability\full function. The instrument has a unique and more attractive outline,molding is more beautiful and convenient operation. The instrument applies high-performance A/D transformer, all the components are SMD surfaced. And all the range positions have overloading protection function,not easy to damage. AC current is measured through the clamp jaw, the rest input through the test lead, all ranges are auto-ranging and can test AC Voltage\DC Voltage\Resistance\Diode and continuity. The meter has "SELECT/HOLD" key for function selection and reading\recordiang for the users during the measurement. Technic Specifications: AC Current 2~20A /200~400A(Auto Range)  AC Voltage 600V(Auto Range) DC Voltage 600V(Auto Range)  Resistance 20MW(Auto Range) Max Display 1999 Range Selection Auto Range Switch Speed 2.5_3 times/sec Polarity  It display "-"for negative polarity input Over Range Display 1 Data Hold Low battery   Continuity Test