Extech 380975 1000 Ampere True RMS AC Power Clamp Meter with Insulation Resistance, and Type K Temperature Probes Measures power up to 600kW, apparent power up to 600kVA and True RMS current and voltage up to 1000A/600V Other functions include mA AC/DC current (via test leads), power factor, resistance, capacitance, frequency and temperature 10,000 count display 100M resistance range for checking insulation 1.6 inch (40mm) jaw opening