B&K Precision 308A Digital Megohmmeter Insulation and Continuity Tester, 250/500/1000V Test Voltages, 2,000 Megohms Insulation Resistance, 2,000 Ohms Low-Resistance, 600V Voltage Digital megohmmeter has three test voltages250, 500, and 1,000Vfor measuring insulation resistance to 2,000 megohms, and also measures low-resistance to 2,000 ohms Measures AC voltage to 600V, lighting a warning indicator when a live circuit is detected Residual voltage is automatically discharged from the circuit under test when the test button is released Overload protection helps prevent damage to the meter Meets IEC safety standard 1010-1 and is rated for CAT III installations to 600V