Vintage General Meters Inc. type MD-1 insulation breakdown test set with backlit meters. Using either a 115Vac or 24-28 Vdc power source, this unit produces from 0Vdc to 15 KVdc and can also be used as a megger. The internal safety reset is presently adjusted for 12 Kv. For extra safety, the unit has been modified for a standard 3 wire grounded cord. Supplied with ac and dc power cords, two test probes and the operation, service and repair instructions (with schematic). It's an old military unit, but it works.