This Extech insulation tester measures up to 10 GOhm with 250 V, 500 V and 1000 V test voltages. Features include Lo-Ohms for testing connections, analog bargraph for viewing trends, AC/DC Voltage measurement to 999 V, manual data record/recall function (9 sets) and live circuit display warning and beeper. Can be used to test motor, transformer windings, instruments and appliances, check for moisture in wire and cable assemblies, safely evaluate a new wiring installation and check for carbon tracking in breakers, relays and switches. Extech insulation testers offer high sensitivity to assure reliable monitoring of low resistance motor windings. Complete with carrying case, test leads and 6 AA batteries.