Voltage, Continuity and Phase Tester with Flashlight The Extech VT10 Multi-Function Voltage Tester has LED AC voltage indications for 24V, 48V, 120V, 208V, 240V, 277V, 480V and 600V and LED DC voltage indications for 6V, 12V, 24V, 36V, 48V, 110V, 220V and 400V. This tester has polarity detection with the LEDs for a positive and negative DC indication. Capable of running a continuity test with an audible tone. Phase rotation test for the motors, two handed operation tester for low impedance testing. Also, this tester has a built-in flashlight for testing in low lit or tight areas. The voltage function operates with out any batteries and it has a rubberized, double-molded IP64 housing.