The Extech 380320 is an Analog Insulation Tester with a large, easy to read analog display. It features a live circuit warning which displays the actual AC voltage measurement. It also includes an automatic discharge circuit, lock power on feature for extended test times, and insulation resistance up to 400 MΩ. Complete with heavy duty test leads, alligator clip test lead, 6 AA batteries, hanging strap, and hard carrying case.