The Hickok/Waekon SST42V Circuit Tester is computer and air bag safe. This tool identifies power, ground and opens on 6V, 12V, 24V and 42V circuits, and is 42V hybrid combatible. Quickly find broken wires, blown fuses, bad switches and more. A super-bright LED headlamp works well for working under dash, under hood or behind door panels. This circuit tester has microprocessor controlled current loading capability for a TRUE test of powers and grounds. A dual audible tone and bicolor LED indicate power, ground or open circuits. Includes: 4" probe extension, screw-on alligator clip and banana plug. Comes in a blow-molded case.