... is made of high definition transparent glass material molded overall , the bottom of the meter is made of quality Aluminium ... It is nothing with direction of the flow of load current,complying with standard IEC62053-21,IEC62052 ... , 120 220, 230, 240, etc.Rated current(A)1.5(6), 2.5(10), 5(20 ... 60HzInternal power consumptionVoltage circuit ≤1.0W 5VA; Current circuit ≤1VA(Ib)Max.operation temperature-40°C ...