B&K Precision 307A Analog Megohmmeter Insulation and Continuity Tester, 250/500/1000V Test Voltages, 400 Megohms Insulation Resistance, 500 Ohms Low-Resistance, 600V Voltage Detection Analog megohmmeter has three test voltages250, 500, and 1,000Vfor measuring insulation resistance to 400 megohms, and also measures low-resistance continuity to 500 ohms Detects AC voltage to 600V, lighting a warning indicator when a circuit is live Residual voltage is automatically discharged from the circuit under test when the test button is released Taut band movement provides prompt, accurate readings Meets IEC safety standard 1010-1 and is rated for CAT III installations to 600V